Is this Intel i7 machine good for LTSpice?

[Joerg]

Folks,

Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
that the Intel i7 is a really good processor for LTSPice. According to
this it looks like the 4790 is the fastest of the bunch:

http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html

So, what do thee say, is the computer in the Costco link below a good
deal for LTSpice purposes?

http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html

It's also available without MS-Office Home & Student 2013 for $100 less
but I found that OpenOffice isn't 100% compatible in the Excel area so
that sounds like an ok deal. My hope is that it can drive two 27"
monitors but I guess I can always add in another graphics card if not.

Reason I am looking at these is that I absolutely positively do not want
any computer with Windows 8 in here and unfortunately that's what many
others come with.

--
Regards, Joerg

http://www.analogconsultants.com/

[Carl Ijames]

Don't know about computation speed, but this link says the video card will
drive 3 monitors:
http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/specifications.
Looking at Dell's site I don't see any mention of expansion slots, and
looking at the one picture with the cover off I really can't see any sockets
beyond the video card, so if any further expansion is important you need to
ask Dell for clarification.

-----
Regards,
Carl Ijames
"Joerg" wrote in message news:cbn0o5...@mid.individual.net...

[John Larkin]

On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
wrote:

I have spent too many hours this weekend tweaking the transient
response of a semi-hysteretic (we call it "hysterical") switchmode
constant-current source. There are about 8 interacting knobs to turn.
At 30 seconds per run, understanding the interactions is impossible.

I want sliders on each of the part values, and I want to see the
waveforms change as I move the sliders, like they were trimpots on a
breadboard and I was looking at a scope. I need maybe 500 times the
compute power that I have now.

Mike should code LT Spice to execute on a high-end video card.


--

John Larkin Highland Technology, Inc

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

[Phil Hobbs]

You can go quite a bit faster with a nice multicore machine--LTspice
lets you choose how many threads to run. My desktop machine (about 3
years old now) runs about 150 Gflops peak. Supermicro is an excellent
vendor.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

[Jan Panteltje]

On a sunny day (Sun, 02 Nov 2014 08:00:36 -0800) it happened John Larkin
<jla...@highlandtechnology.com> wrote in
<0nkc5aljhec5r36pt...@4ax.com>:

Maybe building the real thing with some pots?
But without some theory backing it up how would you know it always works?
And with the theory you do not need the sliders.

I do not see the need for insane speeds, I have used LTspice more than often
the last few days, running on an old Duron 950, fast enough.
maybe you guys are doing something wrong?
:-)

And it is always an approximation, build the real thing too,
needed tweaking with resistors in series, that is analog,
got some nice 25 turn Bourns trimpots from ebay.....

[Joerg]

Carl Ijames wrote:
> Don't know about computation speed, but this link says the video card will
> drive 3 monitors:
> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/specifications.
> Looking at Dell's site I don't see any mention of expansion slots, and
> looking at the one picture with the cover off I really can't see any sockets
> beyond the video card, so if any further expansion is important you need to
> ask Dell for clarification.
>

Looks like you are right:

http://www.dell.com/ed/business/p/xps-8700/pd
http://core0.staticworld.net/images/article/2013/07/1253541_sr-1160-100047019-orig.jpg
http://www.pcworld.com/article/2047487/dell-xps-8700-special-editions-review-a-little-less-performance-for-a-lot-less-cash.html

Quote "There’s only one PCIe x16 slot, which means you won’t be able to
add a second video card to take advantage of Nvidia’s SLI technology".

No slots. There's one more card in the bottom, not sure what that is.
But if the video can drive three monitors it should be fine, I never
added any cards to my current PC either.

[...]

[Joerg]

Only question is, how can one connect two regular OPC monitors to this?

http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-images

[Joerg]

John Larkin wrote:
> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
> wrote:
>
>> Folks,
>>
>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>> that the Intel i7 is a really good processor for LTSPice. According to
>> this it looks like the 4790 is the fastest of the bunch:
>>
>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>
>> So, what do thee say, is the computer in the Costco link below a good
>> deal for LTSpice purposes?
>>
>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>
>> It's also available without MS-Office Home & Student 2013 for $100 less
>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>> that sounds like an ok deal. My hope is that it can drive two 27"
>> monitors but I guess I can always add in another graphics card if not.
>>
>> Reason I am looking at these is that I absolutely positively do not want
>> any computer with Windows 8 in here and unfortunately that's what many
>> others come with.
>
> I have spent too many hours this weekend tweaking the transient
> response of a semi-hysteretic (we call it "hysterical") switchmode
> constant-current source. There are about 8 interacting knobs to turn.
> At 30 seconds per run, understanding the interactions is impossible.
>

That's exactly why I need all the speed I can get.

> I want sliders on each of the part values, and I want to see the
> waveforms change as I move the sliders, like they were trimpots on a
> breadboard and I was looking at a scope. I need maybe 500 times the
> compute power that I have now.
>

I use the .STEP command a lot, sometimes nested. Then I get multiple
sets of curve sets. But often I have to start it at night and see the
results the next morning. The nice thing in winter is that this
pre-heats the office.

> Mike should code LT Spice to execute on a high-end video card.
>

There are so many variants of graphics cards that it would require tons
of work for Mike's team.

[Joerg]

But they should work on their web site some more or get rid of scripting
or whatever. Other than a language selector it shows ... nothing.

[Jim Thompson]

On Sun, 02 Nov 2014 09:28:33 -0800, Joerg <ne...@analogconsultants.com>
wrote:

>John Larkin wrote:
[snip]

>>
>> I have spent too many hours this weekend tweaking the transient
>> response of a semi-hysteretic (we call it "hysterical") switchmode
>> constant-current source. There are about 8 interacting knobs to turn.
>> At 30 seconds per run, understanding the interactions is impossible.
>>
>
>That's exactly why I need all the speed I can get.
>
>
>> I want sliders on each of the part values, and I want to see the
>> waveforms change as I move the sliders, like they were trimpots on a
>> breadboard and I was looking at a scope. I need maybe 500 times the
>> compute power that I have now.
>>
>
>I use the .STEP command a lot, sometimes nested. Then I get multiple
>sets of curve sets. But often I have to start it at night and see the
>results the next morning. The nice thing in winter is that this
>pre-heats the office.
>

[snip]

Mostly I only use LTspice to run other's schematics or to run netlists
generated by PSpice, but I'd hazard a guess...

Either via .STEP or saving and superimposing data files I'm sure you
can generate a family of curves versus your knob twisting (though I
might make the argument that, if you "design" by knob twisting, you're
not much of a designer >:-}

Here's a trick I picked up a few years ago that allows tons of data
runs to be collected into a single postscript file:

Concatenate the following...

header.ps
yourfile1.ps
yourfile2.ps
yourfile3.ps
yourfile4.ps
| |
footer.ps

The result superimposes all your data runs into one postscript file
graph. (I then run the result thru Adobe Acrobat to convert to a
PDF.)

Here are the files you need....

header.ps:

%%
%% First things first, we set up the letter tray. Of course
%% if you wnated another tray, you could change this...
%%
[{
%%BeginFeature: *PageSize Letter
statusdict /lettertray get exec
%%EndFeature
} stopped cleartomark

%%
%% Windows drivers stick a 'control-d' at the end of jobs. This causes
%% many interpreters to think its the end of job (hang over from
serial
%% communication days). So, we define an operator called /4 which does
%% nothing.
%%
(\004) cvn {} bind def

%%
%% lettertray does different things on different interpeters. On Jaws
%% it just changesd the page size, on Adobe it seems to erase the page
%% too. Since we've already set it up once, its safe to zap the
%% definition.
%%
statusdict begin /lettertray {} bind def end

%%
%% Now we store the *original* definitions of the operators we are
%% about to change, in case we need them...
%%
/Mysetpagedevice /setpagedevice load def
/Myshowpage /showpage load def

%%
%% Now, we make sure that the job can't change our setup, which might
%% cause graphics state resets and other embarrasments.
%%
/setpagedevice {pop} bind def

%%
%% we redefine showpage so that it does nothing, this means that the
%% next 'page' will overlay the current page.
%%
/showpage {} bind def




footer.ps:

%%
%% Lastly we emit the *original* showpage definition to 'show' the
page
%%
Myshowpage




...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

[John Larkin]

There's a setting for one or two threads. Is that all?

[Jeff Liebermann]

On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
wrote:

LTspice benchmark on various machines:
<http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>

>Reason I am looking at these is that I absolutely positively do not want
>any computer with Windows 8 in here and unfortunately that's what many
>others come with.

Windoze 8.1 can be made semi-tolerable by putting the start menu back
in and making it look like Windoze 7.
<http://www.classicshell.net>
I've been installing it on all my customers Windoze 8.1 machines and
have had no complaints or problems. If you like wiggly icons on the
Windoze 8.1 start screen, you can do <Shift><Start>.

The damage control version of Windoze 10, that is possibly due some
time in the distant future, restores the start menu:
<http://windows.microsoft.com/en-us/windows/preview>
but otherwise currently looks like Windoze 8.1.

Incidentally, Halloween was the last day that Microsoft will ship
Windoze 7 licenses to OEM's.

The Dell XPS 8700 seems like a nice machine. However, if you want
performance, I suggest you look at an SSD drive for the OS.
<http://www.newegg.com/Internal-SSDs/SubCategory/ID-636>
I've had good luck with Samsung 840 EVO series drives (mostly 250GB).
The ritual is simple. I use Acronis True Image 2014 (not 2015) to
clone the hard disk to the SSD. I then replace the hard disk with the
SSD and test everything. When done, I wipe the hard disk, and install
it as a 2nd hard disk. If I need to return everything to stock, I
have the Acronis True Image 2014 backup image with which to recover
the initial installation. Elapsed time on a typical fast system is
about 1 hr.

Before buying anything, I suggest you try LTspice on the new machine.
This is VERY easy with LTspice which doesn't use the registry or
require admin rights. Just copy the files to a flash drive and it
should work.

One catch. LTspice saves its preferences to:
C:\windows\scad3.ini
which has to be writeable. The fix is to use the
-ini <path>
command line switch, which will:
Specify an .ini file to use other than %WINDIR%\scad3.ini
<http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>







--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Joerg]

Jeff Liebermann wrote:
> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
> wrote:
>
> LTspice benchmark on various machines:
> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>
>> Reason I am looking at these is that I absolutely positively do not want
>> any computer with Windows 8 in here and unfortunately that's what many
>> others come with.
>
> Windoze 8.1 can be made semi-tolerable by putting the start menu back
> in and making it look like Windoze 7.
> <http://www.classicshell.net>
> I've been installing it on all my customers Windoze 8.1 machines and
> have had no complaints or problems. If you like wiggly icons on the
> Windoze 8.1 start screen, you can do <Shift><Start>.
>

Too much risk. I've heard that running legacy software is tough in Win-8
but Win-7 can mostly do it. Not as good as XP.

> The damage control version of Windoze 10, that is possibly due some
> time in the distant future, restores the start menu:
> <http://windows.microsoft.com/en-us/windows/preview>
> but otherwise currently looks like Windoze 8.1.
>
> Incidentally, Halloween was the last day that Microsoft will ship
> Windoze 7 licenses to OEM's.

Any guess how long MS will support Win-7?

> The Dell XPS 8700 seems like a nice machine. However, if you want
> performance, I suggest you look at an SSD drive for the OS.
> <http://www.newegg.com/Internal-SSDs/SubCategory/ID-636>
> I've had good luck with Samsung 840 EVO series drives (mostly 250GB).
> The ritual is simple. I use Acronis True Image 2014 (not 2015) to
> clone the hard disk to the SSD. I then replace the hard disk with the
> SSD and test everything. When done, I wipe the hard disk, and install
> it as a 2nd hard disk. If I need to return everything to stock, I
> have the Acronis True Image 2014 backup image with which to recover
> the initial installation. Elapsed time on a typical fast system is
> about 1 hr.
>

When it comes to PCs I am lazy :-)

I just want to plug it in and go. Re-installing all my stuff takes
enough time already.

> Before buying anything, I suggest you try LTspice on the new machine.
> This is VERY easy with LTspice which doesn't use the registry or
> require admin rights. Just copy the files to a flash drive and it
> should work.

I am quite sure Costco will not let me do this :-)

>
> One catch. LTspice saves its preferences to:
> C:\windows\scad3.ini
> which has to be writeable. The fix is to use the
> -ini <path>
> command line switch, which will:
> Specify an .ini file to use other than %WINDIR%\scad3.ini
> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>
>
>
>
>
>
>


--

Regards, Joerg

http://www.analogconsultants.com/

[Klaus Kragelund]

I have a two year old laptop. I was tired with the slow startup of programs, so I replaced the hard disk with a SSD. Amazing difference in speed. As far as I can see also for the simulations although I did not do a benchmark test.

The Kingston SSD came with a USB connected enclosure to mount the old hard disk in, so the harrdisk was mirrored and no re install of programs was needed

Cheers

Klaus

[Phil Hobbs]

That's because you only have two cores. Mine goes up to 15.

[Phil Hobbs]

Probably a NoScript issue, or something like that. Talk to Alexander at
alvio.com a primo Supermicro reseller, and tell him "Hi" from me.

[John Larkin]

I am halfway through building a breadboard; I'll post pics. I'm after
extreme broadband high impedance output, which is hard to measure on a
breadboard; Spice lets me graph all sorts of currents and nodes, so
it's the best platform for development.

>But without some theory backing it up how would you know it always works?

I'll have to simulate, and then test, the thing over a range of loads.

>And with the theory you do not need the sliders.

I don't have sufficient theoretical skills to tune this circuit. I'm
not sure if anyone does.

>
>I do not see the need for insane speeds, I have used LTspice more than often
>the last few days, running on an old Duron 950, fast enough.
>maybe you guys are doing something wrong?

At 30-50 seconds per run, iteration is slow. Worse, the time lag
wrecks my ability to acquire intuition about what's going on.

>:-)
>
>And it is always an approximation, build the real thing too,
>needed tweaking with resistors in series, that is analog,
>got some nice 25 turn Bourns trimpots from ebay.....

I'll have to tweak resistors and capacitors, and the cap values are
too big for variable capacitors. And, as noted, it would be hard to
instrument.

Here's the current output when the load voltage steps from about 0.5
to 3 volts.

>https://dl.dropboxusercontent.com/u/53724080/Circuits/Current_Sources/Hysterical_A1.jpg

I want it as flat as possible.

The fast ripple is the basic 1.5 MHz switcher frequency. The various
whoopie-doos are from loop dynamics and the chain of progressively
smaller, bias-tee-like damped inductors between the switcher and the
load. The constant-current hysterical switcher is, natively, about 4
or so orders of magnitude too slow for my application.

Everything interacts with everything else; it's like tuning a big LC
filter by hand, never a fun thing to do. Spice helps me acquire at
least some instincts for tuning. Maybe I can fix the cap values and
tune only resistors on the breadboard.

Rob, one of my guys, has a fierce Linux computer just for sims and
FPGA compiles, and he knows how to do automatic iterative parts value
tweaking in a loop around Spice. Maybe he can set up the problem and
run it for a couple of days or weeks.

I could probably step each of the six most important values, maybe 4
steps each, and pick the best waveform. That would be 4096 sims, about
60 hours of computing on my PC.

[John Larkin]

On Sun, 02 Nov 2014 09:28:33 -0800, Joerg <ne...@analogconsultants.com>
wrote:

Just pick one of the Nvidia number cruncher monsters. There are C
compilers available.

You can buy an Nvidia "video" board with no video out; it's just a 200
or something core compute engine.

Maybe the SuperSpice guy is interested. There's money there.

[Spehro Pefhany]

Looks pretty decent for the money, 32G is a sensible amount of RAM-
the RAM speed might be a bit on the low side though. I only research
this stuff when I'm shopping for a new box, but that stands out.

You can get a 1T Samsung SSD for only about $450, which allows you to
leave the mechanical one it comes with (worth < $100) pristine and to
be returned with the computer if necessary (so no proprietary
information can escape).


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

[Tim Williams]

"John Larkin" <jla...@highlandtechnology.com> wrote in message
news:0nkc5aljhec5r36pt...@4ax.com...

> I want sliders on each of the part values, and I want to see the
> waveforms change as I move the sliders, like they were trimpots on a
> breadboard and I was looking at a scope. I need maybe 500 times the
> compute power that I have now.

You can do that in Multisim, but it's single thread only, no faster than
any other simulator.

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

[Jeff Liebermann]

On Sun, 02 Nov 2014 09:53:42 -0800, Joerg <ne...@analogconsultants.com>
wrote:

>Any guess how long MS will support Win-7?

Jan 13, 2015
<http://windows.microsoft.com/en-us/windows/lifecycle>
Extended support means that MS will gladly continue supporting Windoze
7 if you throw money at them. MS is following the Apple policy of
killing everything that's more than 5 years old (except in California,
which is 7 years):
<http://support.apple.com/en-us/ht1752>

>When it comes to PCs I am lazy :-)

That's why I'm still in business to seperate such customers from their
money. Lazy is good for supporting my decadent and lavish lifestyle.

>I just want to plug it in and go. Re-installing all my stuff takes
>enough time already.

It's fairly easy to migrate programs and data from most anything to
Windoze 7.
<http://www.dummies.com/how-to/content/how-to-use-easy-transfer-in-windows-7.html>
<http://windows.microsoft.com/en-us/windows7/products/features/windows-easy-transfer>
However, Easy Transfer disappeared in Windoze 8.1, so you're either on
your own or purchase a 3rd part program to do the dirty work.

>> Before buying anything, I suggest you try LTspice on the new machine.
>> This is VERY easy with LTspice which doesn't use the registry or
>> require admin rights. Just copy the files to a flash drive and it
>> should work.
>
>I am quite sure Costco will not let me do this :-)

It's easier to obtain forgiveness than permission.

Are you really going to spend $1,300+ for a new machine without even a
test drive? Costco has a very good return policy, but you still have
to haul it home, get it running, update, tweak, tune, and then try. If
unacceptable, you get to try and fit everything back into the original
box (which never seems to fit). This is not being lazy.

[Jan Panteltje]

On a sunny day (Sun, 02 Nov 2014 10:21:33 -0800) it happened John Larkin
<jla...@highlandtechnology.com> wrote in
<6erc5ahtpf0buuavb...@4ax.com>:

>I'll have to tweak resistors and capacitors, and the cap values are
>too big for variable capacitors. And, as noted, it would be hard to
>instrument.
>
>Here's the current output when the load voltage steps from about 0.5
>to 3 volts.
>
>>https://dl.dropboxusercontent.com/u/53724080/Circuits/Current_Sources/Hysterical_A1.jpg
>
>I want it as flat as possible.

It looks a bit under-compensated, as if it takes time for it to respond to a load change.
It can probably never be faster than the /\/\/ cycles, but should be possible bette rthan this.
Diff part..

>The fast ripple is the basic 1.5 MHz switcher frequency. The various
>whoopie-doos are from loop dynamics and the chain of progressively
>smaller, bias-tee-like damped inductors between the switcher and the
>load. The constant-current hysterical switcher is, natively, about 4
>or so orders of magnitude too slow for my application.
>
>Everything interacts with everything else; it's like tuning a big LC
>filter by hand, never a fun thing to do. Spice helps me acquire at
>least some instincts for tuning. Maybe I can fix the cap values and
>tune only resistors on the breadboard.
>
>Rob, one of my guys, has a fierce Linux computer just for sims and
>FPGA compiles, and he knows how to do automatic iterative parts value
>tweaking in a loop around Spice. Maybe he can set up the problem and
>run it for a couple of days or weeks.
>
>I could probably step each of the six most important values, maybe 4
>steps each, and pick the best waveform. That would be 4096 sims, about
>60 hours of computing on my PC.

I have never been a PID guy, really, I have a simlilar problem here with frequency stabilization.
been testing large part of the day, reading many papers, got things working,
got severely pissed with Analog Devices (they provide PLL calculation soft that refuses to run under Linux wine,
even seems encryped, takes hour to un-encrypt, then cannot find DLLs), OK,
then I decided to do it in all software and not buy their chip.
I think the software solution can be better than their chip, anyways, experiment is fun :-)
I have coded it, but really need to watch some movie to prevent electronics overdose.

[Jim Thompson]

On Sun, 02 Nov 2014 09:28:33 -0800, Joerg <ne...@analogconsultants.com>
wrote:

[snip]

>
>I use the .STEP command a lot, sometimes nested. Then I get multiple
>sets of curve sets. But often I have to start it at night and see the
>results the next morning. The nice thing in winter is that this
>pre-heats the office.
>
>

[snip]

Here's how I handle a system that has multiple, interrelated
adjustments. I just .STEP CASE from 1 to 4...

.PARAM VDD={ROW1+ROW2+ROW3+ROW4}
+ B1V8={IF(CASE==3,1,0)+IF(CASE==4,1,0)}
+ S3V3={IF(CASE==2,1,0)+IF(CASE==4,1,0)}
+ CASE=4
+ PVDD=1 ; 0=TYP, -1=MIN, 1=MAX
ROW1={IF((CASE==1)&(PVDD==0),3.3,0)+IF((CASE==1)&(PVDD==-1),2.5,0)+IF((CASE==1)&(PVDD==1),3.6,0)}
ROW2={IF((CASE==2)&(PVDD==0),2.5,0)+IF((CASE==2)&(PVDD==-1),2.35,0)+IF((CASE==2)&(PVDD==1),2.75,0)}
ROW3={IF((CASE==3)&(PVDD==0),3.0,0)+IF((CASE==3)&(PVDD==-1),2.7,0)+IF((CASE==3)&(PVDD==1),3.3,0)}
ROW4={IF((CASE==4)&(PVDD==0),3.3,0)+IF((CASE==4)&(PVDD==-1),3.0,0)+IF((CASE==4)&(PVDD==1),3.6,0)}

[rickman]

On 11/2/2014 10:25 AM, Joerg wrote:
> Folks,
>
> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
> that the Intel i7 is a really good processor for LTSPice. According to
> this it looks like the 4790 is the fastest of the bunch:
>
> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>
> So, what do thee say, is the computer in the Costco link below a good
> deal for LTSpice purposes?
>
> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html

Hard to say. The devil is in the details. I have an i7 and I'm not
convinced it is much better if any than other CPUs for most tasks. One
problem with the quad core is that that each core still runs at the same
speed as a dual core or even slower due to the contention for memory
bandwidth. That is why I got a laptop with separate graphic memory.
But overall I don't see big speed improvements. I'd be willing to bet
you won't see a huge difference between this machine and one costing a
few hundred dollars less. BTW, do you really need a new monitor? I
expect you can save a couple hundred more by getting a unit without
monitor.

> It's also available without MS-Office Home & Student 2013 for $100 less
> but I found that OpenOffice isn't 100% compatible in the Excel area so
> that sounds like an ok deal. My hope is that it can drive two 27"
> monitors but I guess I can always add in another graphics card if not.

I use LibreOffice which is the same package from the developers who
jumped ship at Oracle to continue development of OpenOffice the way they
think is best. I don't see compatibility issues and 90% of what I use
office for is the spreadsheet.

> Reason I am looking at these is that I absolutely positively do not want
> any computer with Windows 8 in here and unfortunately that's what many
> others come with.

Get something tailor made. You can get both the best machine and the
cheapest that way. After all, they are all made from the same parts.
It is just a question of who puts them together.

--

Rick

[upsid...@downunder.com]

On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
wrote:

>Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>that the Intel i7 is a really good processor for LTSPice. According to
>this it looks like the 4790 is the fastest of the bunch:
>
>http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>
>So, what do thee say, is the computer in the Costco link below a good
>deal for LTSpice purposes?
>
>http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html

How well does LTSpice spread simulation cycles between multiple
processors and multiple cores (Hyperthreading etc.) ?

[rickman]

On 11/2/2014 12:53 PM, Joerg wrote:
> Jeff Liebermann wrote:
>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
>> wrote:
>>
>> LTspice benchmark on various machines:
>> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>>
>>> Reason I am looking at these is that I absolutely positively do not want
>>> any computer with Windows 8 in here and unfortunately that's what many
>>> others come with.
>>
>> Windoze 8.1 can be made semi-tolerable by putting the start menu back
>> in and making it look like Windoze 7.
>> <http://www.classicshell.net>
>> I've been installing it on all my customers Windoze 8.1 machines and
>> have had no complaints or problems. If you like wiggly icons on the
>> Windoze 8.1 start screen, you can do <Shift><Start>.
>>
>
> Too much risk. I've heard that running legacy software is tough in Win-8
> but Win-7 can mostly do it. Not as good as XP.

What legacy software? I have Windows 8 and I'm not having problems
running anything I ran on my old Vista laptop.

> When it comes to PCs I am lazy :-)
>
> I just want to plug it in and go. Re-installing all my stuff takes
> enough time already.

I hear you. The big problem I had with setting up my Win 8 laptop was
that a lot of the freeware has become burdened with ads, toolbars and
other malware to the point I'm not willing to use it.

>> Before buying anything, I suggest you try LTspice on the new machine.
>> This is VERY easy with LTspice which doesn't use the registry or
>> require admin rights. Just copy the files to a flash drive and it
>> should work.
>
> I am quite sure Costco will not let me do this :-)

You can try finding the computer salesperson in the store. They are
limited by store policy of course, but I have met a few who were very
willing to help as best they could.

>> One catch. LTspice saves its preferences to:
>> C:\windows\scad3.ini
>> which has to be writeable. The fix is to use the
>> -ini <path>
>> command line switch, which will:
>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>

I need to note this somewhere. Writing to the Windows directory is a
*very* bad idea. I can't tell you how many developers do all sorts of
things they aren't supposed to under windows. That is the actual cause
of many problems people have running older software under Windows. They
don't listen to the people providing them with the OS!

--

Rick

[Carl Ijames]

"Joerg" wrote in message news:cbn7m2...@mid.individual.net...

==============================================================================

That's the gotcha, you need a different cable to each monitor. I'm no
expert, but I have an ATI Radeon HD5670 that supports 3 monitors and has the
same three connectors so I have my main monitor connected with the DVI-D
cable and my TV set connected with HDMI so I can watch video files on the TV
(I have a Hauppage tuner card and use my pc as dvr). I don't use the third
output. The installation guide shows pictures of adaptors from hdmi and
svga to dvd-d so if you used those you could use all dvd-I monitors, but
I've never looked for them so can't give any advice there. There might be a
lower max resolution on the svga output. The video driver lets me choose
which monitor is which and how to arrange them., so that is painless.

-----
Regards,
Carl Ijames

[Lasse Langwadt Christensen]

I'd expect that you can connect a monitor to each of the three outputs,
VGA,DVI,HDMI. I have an old geforce and that's how that works

VGA is not much use, but unless you want to watch something from Hollywood
DVI and HDMI is the same thing


-Lasse

[DecadentLinuxUserNumeroUno]

On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>

Gave us:

>Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>that the Intel i7 is a really good processor for LTSPice. According to
>this it looks like the 4790 is the fastest of the bunch:
>
>http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html

That actually looks like a really nice deal. You can't go wrong.
Mine cost me $2500 and took over a year to build as budgets tightened.

I'll bet my 3930K beats it though.

The newer fabs have higher GHz rates, but are not as fast as their
first series were, which the smaller fabs replaced..

I have 6x2 cores, and I don't even know if they do that any more
except on Xeons.

I scream past all the benchmarks. Two more cores really makes a
difference. I beat machines pegging faster raw "speeds" all the time.
Mainly because they only have 4x2 cores.

Not cheap. The i7-3930K was $695, and the X79 Mobo under it was $400.
The 32GB RAM was not cheap either for 2133MHz, And that was before the
2400MHz stuff appeared. I can still upgrade the GPU and the RAM and get
even faster.

Since I cannot afford to put $1000 into a Titan video card, I miss on
a few benchmarks with my $250 GTX650.

[DecadentLinuxUserNumeroUno]

On Sun, 02 Nov 2014 09:46:45 -0800, Jeff Liebermann <je...@cruzio.com>
Gave us:

>
>The Dell XPS 8700 seems like a nice machine. However, if you want
>performance, I suggest you look at an SSD drive for the OS.

Even better than those are the mSATA drives and now, the best... the
M.2 drives.

Not much bigger than a couple of air mail stamps (I date myself).

Way faster than the 2.5" form factor SSD "laptop drive" replacement
family.

Even an mSATA drive in a USB3 enclosure/interface plugged into a USB 2
port boots up faster. As you can see, I am impressed.
You would be as well.

I would look into M.2 drives as they are the hot, emerging storage
tech right now, and they DO make a difference.

Even with your SSD variety, machines scream in benchmarks.

And this is OLD stuff. Things are way faster now than even that.

http://www.youtube.com/watch?v=eULFf6F5Ri8

[Jan Panteltje]

On a sunny day (Sun, 2 Nov 2014 12:09:54 -0800 (PST)) it happened Lasse
Langwadt Christensen <lang...@fonz.dk> wrote in
<dc45b7d4-b977-43ae...@googlegroups.com>:

>VGA is not much use, but unless you want to watch something from Hollywood=

VGA is still very useful,
I have one HD monitor with an extra VGA to a PC at the other side of the room.
Its faster than ssh -Y and does not load the network.
It displays lots of technical stuff that I run remote via wireless keyboard and mouse on that PC.

[John Larkin]

On Sun, 02 Nov 2014 19:02:35 GMT, Jan Panteltje
<pNaonSt...@yahoo.com> wrote:

>On a sunny day (Sun, 02 Nov 2014 10:21:33 -0800) it happened John Larkin
><jla...@highlandtechnology.com> wrote in
><6erc5ahtpf0buuavb...@4ax.com>:
>
>>I'll have to tweak resistors and capacitors, and the cap values are
>>too big for variable capacitors. And, as noted, it would be hard to
>>instrument.
>>
>>Here's the current output when the load voltage steps from about 0.5
>>to 3 volts.
>>
>>>https://dl.dropboxusercontent.com/u/53724080/Circuits/Current_Sources/Hysterical_A1.jpg
>>
>>I want it as flat as possible.
>
>It looks a bit under-compensated, as if it takes time for it to respond to a load change.
>It can probably never be faster than the /\/\/ cycles, but should be possible bette rthan this.
>Diff part..

I'm switching at 1.5 MHz and I want constant current for load steps in
the picosecond time domain.

>
>>The fast ripple is the basic 1.5 MHz switcher frequency. The various
>>whoopie-doos are from loop dynamics and the chain of progressively
>>smaller, bias-tee-like damped inductors between the switcher and the
>>load. The constant-current hysterical switcher is, natively, about 4
>>or so orders of magnitude too slow for my application.
>>
>>Everything interacts with everything else; it's like tuning a big LC
>>filter by hand, never a fun thing to do. Spice helps me acquire at
>>least some instincts for tuning. Maybe I can fix the cap values and
>>tune only resistors on the breadboard.
>>
>>Rob, one of my guys, has a fierce Linux computer just for sims and
>>FPGA compiles, and he knows how to do automatic iterative parts value
>>tweaking in a loop around Spice. Maybe he can set up the problem and
>>run it for a couple of days or weeks.
>>
>>I could probably step each of the six most important values, maybe 4
>>steps each, and pick the best waveform. That would be 4096 sims, about
>>60 hours of computing on my PC.
>
>
>I have never been a PID guy, really, I have a simlilar problem here with frequency stabilization.
>been testing large part of the day, reading many papers, got things working,
>got severely pissed with Analog Devices (they provide PLL calculation soft that refuses to run under Linux wine,
>even seems encryped, takes hour to un-encrypt, then cannot find DLLs), OK,
>then I decided to do it in all software and not buy their chip.
>I think the software solution can be better than their chip, anyways, experiment is fun :-)
>I have coded it, but really need to watch some movie to prevent electronics overdose.
>

The switcher is hysteretic, so there's no PID loop. Being hysteretic
means there's no loop compensation to get just-right, and it also
means that the switcher is fast and has no memory of the past; every
switch cycle stands on its own.

I tried a true hysteretic switcher: current sense resistor, diff gain,
schmitt comparator, mosfet driver. That works, but the frequency
varies all over the place, which has bad side effects. We had a
brainstorm meeting and came up with the hysterical converter. A dflop
drives the synchronous switching fets. We clock it ON at 1.5 MHz and
let the sense current resistor/amp/comparator clear it OFF when the
current hits the setpoint. That results in fixed-frequency PWM, but
with no PID or other memory in the loop. (I'm sure the idea has been
invented many times before.)

By moving a couple of wires, that can be converted to a first-order
delta-sigma loop. It's fun, but has a lot more current ripple than the
clocked hysterical converter.

The current-sense resistor has to be small to keep power dissipation
down, so we need a ton of differential gain, and there will be volts
of 1.5 MHz triangular common-mode junk on the resistor. A MiniCircuits
balun seems (in sim) to cut the common-mode noise down by about 20:1.

Like all RF folks, their parts are grossly underspecified. If you want
to know the winding and leakage inductances of their parts, you have
to measure them. RF is more like plumbing than engineering.

What, me ramble?

[Lasse Langwadt Christensen]

sure it is better than nothing, i.e. as an extra free input on a monitor
But if given a choice you wouldn't want to use VGA

-Lasse

[Jan Panteltje]

On a sunny day (Sun, 02 Nov 2014 12:39:52 -0800) it happened John Larkin
<jla...@highlandtechnology.com> wrote in
<6b4d5al4b453j1af4...@4ax.com>:

>On Sun, 02 Nov 2014 19:02:35 GMT, Jan Panteltje
><pNaonSt...@yahoo.com> wrote:
>
>>On a sunny day (Sun, 02 Nov 2014 10:21:33 -0800) it happened John Larkin
>><jla...@highlandtechnology.com> wrote in
>><6erc5ahtpf0buuavb...@4ax.com>:
>>
>>>I'll have to tweak resistors and capacitors, and the cap values are
>>>too big for variable capacitors. And, as noted, it would be hard to
>>>instrument.
>>>
>>>Here's the current output when the load voltage steps from about 0.5
>>>to 3 volts.
>>>
>>>>https://dl.dropboxusercontent.com/u/53724080/Circuits/Current_Sources/Hysterical_A1.jpg
>>>
>>>I want it as flat as possible.
>>
>>It looks a bit under-compensated, as if it takes time for it to respond to a load change.
>>It can probably never be faster than the /\/\/ cycles, but should be possible bette rthan this.
>>Diff part..
>
>I'm switching at 1.5 MHz and I want constant current for load steps in
>the picosecond time domain.

Yes, OK, then the switcher wil have to swicth off early, or you need to add some analog series regulator.

Yes, I have done that too...

>I tried a true hysteretic switcher: current sense resistor, diff gain,
>schmitt comparator, mosfet driver. That works, but the frequency
>varies all over the place, which has bad side effects. We had a
>brainstorm meeting and came up with the hysterical converter. A dflop
>drives the synchronous switching fets. We clock it ON at 1.5 MHz and
>let the sense current resistor/amp/comparator clear it OFF when the
>current hits the setpoint. That results in fixed-frequency PWM, but
>with no PID or other memory in the loop. (I'm sure the idea has been
>invented many times before.)

This is what I do here:
http://panteltje.com/panteltje/pic/pwr_pic/
there is a current sense transformer, but also a current sense resistor that triggers a comparator
that switches of the MOSFET.
The problem is the energy in the inductors and capacitors will NOT suddenly disapear,
it takes time.
In the sixties I did that (much slower in those days) with an analog transistor series regulator after a thyristor switcher
where the thyristor switcher on average held the voltage over the series transistor as low as possible (just above the ripple)
that was for the telco here.
I dunno what you dissipation issues would be.

>By moving a couple of wires, that can be converted to a first-order
>delta-sigma loop. It's fun, but has a lot more current ripple than the
>clocked hysterical converter.
>
>The current-sense resistor has to be small to keep power dissipation
>down, so we need a ton of differential gain, and there will be volts
>of 1.5 MHz triangular common-mode junk on the resistor. A MiniCircuits
>balun seems (in sim) to cut the common-mode noise down by about 20:1.
>
>Like all RF folks, their parts are grossly underspecified. If you want
>to know the winding and leakage inductances of their parts, you have
>to measure them. RF is more like plumbing than engineering.
>
>What, me ramble?

Me too, I am watching 'red' with whatshisname.

[Martin Riddle]

DVI? You can get a Display port -> DVI adaptor. Dell sends them out
with their business laptops.

Cheers

[risskovboli...@gmail.com]

Or just plug it into Orcad PSpice, which has an optimizer option, to fit the response to whatever you need. Start simulation in the afternoon, drink beer, and show up for the solution in the morning. Not very informative theory wise, but it get the job done

Cheers

Klaus

[Lasse Langwadt Christensen]

it is HDMI, apart from encryption and audio it is the same as DVI


-Lasse

[Jeff Liebermann]

On Sun, 02 Nov 2014 14:56:04 -0500, rickman <gnu...@gmail.com> wrote:

>On 11/2/2014 12:53 PM, Joerg wrote:
>> Too much risk. I've heard that running legacy software is tough in Win-8
>> but Win-7 can mostly do it. Not as good as XP.

>What legacy software? I have Windows 8 and I'm not having problems
>running anything I ran on my old Vista laptop.

I recently awarded myself a short vacation in honor my burning a huge
amount of time getting old software to run nicely on Windoze 8.1.
Specifically, the DOS versions of various fiduciary programs dating
1996 through 2002, which the customer insisted had to run even though
later versions worked just fine. The problem was that the tax rules
and tables all changed over the years and they wanted the original
versions. I ended up running them under DOSbox, which was originally
designed to run ancient games, but works equally well with ancient
business applications:
<http://www.dosbox.com/status.php?show_status=1>
I also tried them under VMware and VirtualBox, both of which worked
nicely, but DOSbox is easier and faster.

Another horror was Office 2003 on Windoze 8.1. It installs, updates,
loads, and looks like it might work, but eventually crashes. All I
really needed was Outlook 2003, but that would hang after polling for
mail a few times. I probably could have figured out the problem, but
convinced the customer that Mozilla Thunderbird would be a suitable
option.

Then, there's WordPerfect 12 which I think was introduced in 2002.
Amazingly, it worked 99%. However, the 1% was fatal. Windoze file
association would not start WP12 if I double clicked on a WPD file (or
any of the other WP files). It took a while to figure out that WP12
was trying to use an ancient ODBC version, which required that WP12
beg permission of the Windoze security abomination before it would
condescend to even supply an error message. Fixed by running WP12 as
administrator, which by passes most of the security mess.

I guess the moral here is to not try to run 12+ year old software on
Windoze 8.1. My mistake was assuming that since all the
aforementioned software ran just fine in Windoze 7, the new and
improved Windoze 8.1 couldn't possibly break something that already
worked so well.

>>> One catch. LTspice saves its preferences to:
>>> C:\windows\scad3.ini
>>> which has to be writeable. The fix is to use the
>>> -ini <path>
>>> command line switch, which will:
>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>

>I need to note this somewhere. Writing to the Windows directory is a
>*very* bad idea.

It was standard procedure in Windoze 3.1, where almost all
applications dropped pick_a_name.ini files in the C:\Windows\
directory. I do have to admit it was handy as the files were easy to
find and save. The new and improved versions of Windoze hide these
config files in either the registry, or bury them 5 directory layers
deep, where few can find them without specialized tools or inside
information.

>I can't tell you how many developers do all sorts of
>things they aren't supposed to under windows. That is the actual cause
>of many problems people have running older software under Windows. They
>don't listen to the people providing them with the OS!

LTspice (aka SwitcherCAD) is a rather old program, with many of the
traditions of Windoze 3.1 still present. If you don't like that, try
running some of the various NEC antenna modeling programs, that still
use the terms "card" and "deck" from the Hollerith punch card era. The
common mantra is the same everywhere... if it works, don't touch it.



Looking at the benchmarks at:
<http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
my Dell Optiplex 755 clunker runs the 3 benchmarks at:
14.5 7.6 3.6
If I upgrade to the fastest machine on the list:
4.0 2.9 1.0
or roughly 3 times faster. Might be worth $1200+.

The database is at:
<https://groups.yahoo.com/neo/groups/LTspice/database/2/edit>
and shows no Windoze 8.1 benchmarks and no SSD, so those will remain
an unknown. The benchmark files and instructions are at:
<https://groups.yahoo.com/neo/groups/LTspice/files/%20Examples/Benchmark/>
If you run the benchmark, be sure to add it to the database.

[Jeff Liebermann]

On Sun, 02 Nov 2014 14:28:57 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:

>Looking at the benchmarks at:
><http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>my Dell Optiplex 755 clunker runs the 3 benchmarks at:
> 14.5 7.6 3.6
>If I upgrade to the fastest machine on the list:
> 4.0 2.9 1.0
>or roughly 3 times faster. Might be worth $1200+.

I ran the benchmarks on my Dell Optiplex 960 (XP-SP3, E8500 3.2GHz,
4GB RAM, 1TB drive).
10.0 11.2 2.5
So, $1200 will get me about 2.5 times faster (ignoring some kind of
problem with the Mic2 test).

[Jeff Liebermann]

On Sun, 02 Nov 2014 12:27:52 -0800, DecadentLinuxUserNumeroUno
<DL...@DecadentLinuxUser.org> wrote:

> Even better than those are the mSATA drives and now, the best... the
>M.2 drives.
> Not much bigger than a couple of air mail stamps (I date myself).
> Way faster than the 2.5" form factor SSD "laptop drive" replacement
>family.

The SSD drive I recommended comes in both SATA3 and mSATA
configurations:
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd840evo/overview_mSATA.html>
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd840evo/overview.html>
The specs look fairly close:
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd840evo/specifications.html>

I have an older mSATA drive in my Acer C720 running Linux. Very very
very very fast, but I haven't compared it with a SATA3 drive.

[Maynard A. Philbrook Jr.]

In article <k4pc5ad6p89qps1bl...@4ax.com>,
je...@cruzio.com says...

>
> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
> wrote:
>

> LTspice benchmark on various machines:
> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>

> >Reason I am looking at these is that I absolutely positively do not want
> >any computer with Windows 8 in here and unfortunately that's what many
> >others come with.
>

> Windoze 8.1 can be made semi-tolerable by putting the start menu back
> in and making it look like Windoze 7.
> <http://www.classicshell.net>
> I've been installing it on all my customers Windoze 8.1 machines and
> have had no complaints or problems. If you like wiggly icons on the
> Windoze 8.1 start screen, you can do <Shift><Start>.
>

> The damage control version of Windoze 10, that is possibly due some
> time in the distant future, restores the start menu:
> <http://windows.microsoft.com/en-us/windows/preview>
> but otherwise currently looks like Windoze 8.1.
>
> Incidentally, Halloween was the last day that Microsoft will ship
> Windoze 7 licenses to OEM's.

>
> The Dell XPS 8700 seems like a nice machine. However, if you want
> performance, I suggest you look at an SSD drive for the OS.

> <http://www.newegg.com/Internal-SSDs/SubCategory/ID-636>
> I've had good luck with Samsung 840 EVO series drives (mostly 250GB).
> The ritual is simple. I use Acronis True Image 2014 (not 2015) to
> clone the hard disk to the SSD. I then replace the hard disk with the
> SSD and test everything. When done, I wipe the hard disk, and install
> it as a 2nd hard disk. If I need to return everything to stock, I
> have the Acronis True Image 2014 backup image with which to recover
> the initial installation. Elapsed time on a typical fast system is
> about 1 hr.

>
> Before buying anything, I suggest you try LTspice on the new machine.
> This is VERY easy with LTspice which doesn't use the registry or
> require admin rights. Just copy the files to a flash drive and it
> should work.
>

> One catch. LTspice saves its preferences to:
> C:\windows\scad3.ini
> which has to be writeable. The fix is to use the
> -ini <path>
> command line switch, which will:
> Specify an .ini file to use other than %WINDIR%\scad3.ini
> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>

I have a 17-xxx XPS 8700, LTSPICE works just dandy on it.

Jamie

[rickman]

On 11/2/2014 5:28 PM, Jeff Liebermann wrote:
> On Sun, 02 Nov 2014 14:56:04 -0500, rickman <gnu...@gmail.com> wrote:
>
>>>> One catch. LTspice saves its preferences to:
>>>> C:\windows\scad3.ini
>>>> which has to be writeable. The fix is to use the
>>>> -ini <path>
>>>> command line switch, which will:
>>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>
>> I need to note this somewhere. Writing to the Windows directory is a
>> *very* bad idea.
>
> It was standard procedure in Windoze 3.1, where almost all
> applications dropped pick_a_name.ini files in the C:\Windows\
> directory.

Yes, and Windows 3.1 crashed on a regular basis for about any reason
whatsoever just like 95, 98 and ME.

MS has been telling developers since Win2000 and maybe since NT to not
put data files in the Windows or Program Files directories. Many chose
to ignore this which wasn't enforced until Vista and became one of the
things everyone loves to hate about Vista.

> I do have to admit it was handy as the files were easy to
> find and save. The new and improved versions of Windoze hide these
> config files in either the registry, or bury them 5 directory layers
> deep, where few can find them without specialized tools or inside
> information.

Windows doesn't put anything from an app in the registry. That is up to
the app to decide. Getting to these directories is easy if they used
the right location, C:\ProgramData. Instead they continue to use
C:\Program Files and now with Win8 MS puts the files in the long path
name you list, but I believe they can be reached transparently through
the path C:\Program Files So the best of both worlds.

If the app puts them somewhere else, don't blame windows.

>> I can't tell you how many developers do all sorts of
>> things they aren't supposed to under windows. That is the actual cause
>> of many problems people have running older software under Windows. They
>> don't listen to the people providing them with the OS!
>
> LTspice (aka SwitcherCAD) is a rather old program, with many of the
> traditions of Windoze 3.1 still present. If you don't like that, try
> running some of the various NEC antenna modeling programs, that still
> use the terms "card" and "deck" from the Hollerith punch card era. The
> common mantra is the same everywhere... if it works, don't touch it.

These programs have been updated many, many times since Windows 3.1.
Windows NT, 2k, XP, Vista, 7, 8 and 8.1 aren't even the same OS as the
3.1 tree which was ended when XP was released. Stick with the old
habits and blame yourself or your program maintainer.

I use some open source Windows software that does the same crap and I am
very vocal about the cause and the fix for the problem. Few of the
developers are interested though. Now that 8 makes this (using Program
Files for data) work adequately they no longer have a need to change it.

If you are relying on programming habits from over 20 years ago, then
you will have to stew in your own soup.

> Looking at the benchmarks at:
> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
> my Dell Optiplex 755 clunker runs the 3 benchmarks at:
> 14.5 7.6 3.6
> If I upgrade to the fastest machine on the list:
> 4.0 2.9 1.0
> or roughly 3 times faster. Might be worth $1200+.
>
> The database is at:
> <https://groups.yahoo.com/neo/groups/LTspice/database/2/edit>
> and shows no Windoze 8.1 benchmarks and no SSD, so those will remain
> an unknown. The benchmark files and instructions are at:
> <https://groups.yahoo.com/neo/groups/LTspice/files/%20Examples/Benchmark/>
> If you run the benchmark, be sure to add it to the database.

SSD is great for anything that uses virtual memory (god forbid) or runs
for a short time after taking time to load. I would not expect spice to
have issues with disk speed except I guess the graph data is stored on
disk maybe? I seem to recall some of my simulations generating a lot of
data which would have easily overflowed the 3 GB of RAM in my machine
after the OS got done with it.

--

Rick

[miso]

I'm on a quad core Xeon, which means I can have 8 threads. Also a Supermicro
motherboard with 32G of error correcting RAM. Basically a low end
workstation.

LT Spice has been multithreaded for about 5 years now, but the nature of
spice simulation won't lead to a linear speed up with the number of cores.
In fact, your setting of three makes sense based on system monitor analysis.

If you go with error detection and correction, you need a server grade mobo
like a Supermicro. Not all boards that can use such RAM have the ability to
report back on the amount of correction that occurs.

Regarding:

"I have spent too many hours this weekend tweaking the transient
response of a semi-hysteretic (we call it "hysterical") switchmode
constant-current source. There are about 8 interacting knobs to turn.
At 30 seconds per run, understanding the interactions is impossible."

Spice is not a design tool. It is a verification tool.

[miso]

Joerg wrote:

>
> There are so many variants of graphics cards that it would require tons
> of work for Mike's team.
>

It isn't the graphics card as much as the standard of acceleration. ATI and
Nvidia use different standards.

NGspice has Cuda support, which means you need Nvidia.
> http://ngspice.sourceforge.net/

You also need an OS that supports CUDA.

[John Larkin]

Of course it's a design tool. Why spend a half hour cranking out a
voltage divider network with a calculator, when you can Spice and
fiddle a solution in a few minutes?

Is a calculator a design tool? Is an equation a design tool?

[miso]

Jeff Liebermann wrote:

> On Sun, 02 Nov 2014 12:27:52 -0800, DecadentLinuxUserNumeroUno
> <DL...@DecadentLinuxUser.org> wrote:
>
>> Even better than those are the mSATA drives and now, the best... the
>>M.2 drives.
>> Not much bigger than a couple of air mail stamps (I date myself).
>> Way faster than the 2.5" form factor SSD "laptop drive" replacement
>>family.
>
> The SSD drive I recommended comes in both SATA3 and mSATA
> configurations:
>
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd840evo/overview_mSATA.html>
>
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd840evo/overview.html>
> The specs look fairly close:
>
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd840evo/specifications.html>
>
> I have an older mSATA drive in my Acer C720 running Linux. Very very
> very very fast, but I haven't compared it with a SATA3 drive.
>

The Samsung 840 series has a speed bug. The fix is in flux, so it is best to
do an internet search for this issue. Samsung released a windows program to
"fix" the problem.

I unfortunately have the 840 in this PC but I run linux, so their fix isn't
so handy.

[Jeff Liebermann]

On Sun, 02 Nov 2014 21:08:42 -0800, miso <mi...@sushi.com> wrote:

>The Samsung 840 series has a speed bug. The fix is in flux, so it is best to
>do an internet search for this issue. Samsung released a windows program to
>"fix" the problem.
>
>I unfortunately have the 840 in this PC but I run linux, so their fix isn't
>so handy.

The Linux fix is on the Samsung web pile in the form of a bootable CD:
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/support/downloads.html>
Near bottom of page. I've only done the Windoze version once. When
it works, it's quite simple. However, if the "advanced mode" is
required, it's an ordeal. As always, make an image backup before
doing anything this radical.

[DecadentLinuxUserNumeroUno]

On Sun, 02 Nov 2014 21:08:42 -0800, miso <mi...@sushi.com> Gave us:

SNIP

>
>The Samsung 840 series has a speed bug. The fix is in flux, so it is best to
>do an internet search for this issue. Samsung released a windows program to
>"fix" the problem.

No bugs in these speed demons from them...

http://www.amazon.com/Samsung-XP941-512GB-PCIe-MZHPU512HCGL/dp/B00JOSM3TK

>I unfortunately have the 840 in this PC but I run linux, so their fix isn't
>so handy.

Bet they are still faster than the Corsair and other counterparts from
the same mfg era.

[Jasen Betts]

On 2014-11-02, Joerg <ne...@analogconsultants.com> wrote:

> Only question is, how can one connect two regular OPC monitors to this?
>
> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-images

Assuming you consider VGA to be irregular use a HDMI to DVI cable for
the other,

--
umop apisdn

[DecadentLinuxUserNumeroUno]

On 3 Nov 2014 06:20:45 GMT, Jasen Betts <ja...@xnet.co.nz> Gave us:

Most video cards even come with an adapter these days.

[Jasen Betts]

On 2014-11-03, rickman <gnu...@gmail.com> wrote:
> On 11/2/2014 5:28 PM, Jeff Liebermann wrote:
>> On Sun, 02 Nov 2014 14:56:04 -0500, rickman <gnu...@gmail.com> wrote:
>>
>>>>> One catch. LTspice saves its preferences to:
>>>>> C:\windows\scad3.ini
>>>>> which has to be writeable. The fix is to use the
>>>>> -ini <path>
>>>>> command line switch, which will:
>>>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>>
>>> I need to note this somewhere. Writing to the Windows directory is a
>>> *very* bad idea.
>>
>> It was standard procedure in Windoze 3.1, where almost all
>> applications dropped pick_a_name.ini files in the C:\Windows\
>> directory.
>
> Yes, and Windows 3.1 crashed on a regular basis for about any reason
> whatsoever just like 95, 98 and ME.
>
> MS has been telling developers since Win2000 and maybe since NT to not
> put data files in the Windows or Program Files directories. Many chose
> to ignore this which wasn't enforced until Vista and became one of the
> things everyone loves to hate about Vista.

? AFAIK Microsoft software is still putting data files there.


--
umop apisdn

[miso]

Jeff Liebermann wrote:

> On Sun, 02 Nov 2014 21:08:42 -0800, miso <mi...@sushi.com> wrote:
>
>>The Samsung 840 series has a speed bug. The fix is in flux, so it is best
>>to do an internet search for this issue. Samsung released a windows
>>program to "fix" the problem.
>>
>>I unfortunately have the 840 in this PC but I run linux, so their fix
>>isn't so handy.
>
> The Linux fix is on the Samsung web pile in the form of a bootable CD:
>
<http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/support/downloads.html>
> Near bottom of page. I've only done the Windoze version once. When
> it works, it's quite simple. However, if the "advanced mode" is
> required, it's an ordeal. As always, make an image backup before
> doing anything this radical.
>

Thanks. I downloaded the ISO and the instructions.

In the dark ages, you would get a file to put on a floppy to upgrade
firmware. Then the manufactures decided that they would just distribute a
windows program. Nice, but if you don't run windows, well not so nice.

My blueray has new firmware.
> http://www.lg.com/us/support-product/lg-WH14NS40
Only windows solutions. Now it isn't like I don't have a windows box handy,
but this shouldn't be necessary. If windows wasn't so damn expensive, I
could dual boot everything, but I don't like paying the Microsoft tax. I
have three copies of win7 pro. Enough is enough.\

I'm going to research the firmware upgrade path prior to buying any more
peripherals.

[miso]

John Larkin wrote:

>>Spice is not a design tool. It is a verification tool.
>>
>>
>
> Of course it's a design tool. Why spend a half hour cranking out a
> voltage divider network with a calculator, when you can Spice and
> fiddle a solution in a few minutes?
>
> Is a calculator a design tool? Is an equation a design tool?
>
>

A voltage divider. We're talking Ohm's law here. You would really resort to
Spice to design something that can be done simply with middle school
algebra?

Have I used Spice to analyze a resistor divider? Actually yes, but in finite
element analysis to simulate a laser trim procedure. The basic networks are
designed by hand.

[Phil Hobbs]

On 11/02/2014 01:17 PM, Phil Hobbs wrote:
> On 11/2/2014 12:45 PM, John Larkin wrote:
>> On Sun, 02 Nov 2014 11:06:30 -0500, Phil Hobbs
>> <ho...@electrooptical.net> wrote:

>>
>>> On 11/2/2014 11:00 AM, John Larkin wrote:
>>>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
>>>> wrote:
>>>>

>>>>> Folks,
>>>>>
>>>>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt
>>>>> stated
>>>>> that the Intel i7 is a really good processor for LTSPice. According to
>>>>> this it looks like the 4790 is the fastest of the bunch:
>>>>>
>>>>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>>>>
>>>>>
>>>>> So, what do thee say, is the computer in the Costco link below a good
>>>>> deal for LTSpice purposes?
>>>>>
>>>>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>>>>
>>>>>
>>>>> It's also available without MS-Office Home & Student 2013 for $100
>>>>> less
>>>>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>>>>> that sounds like an ok deal. My hope is that it can drive two 27"
>>>>> monitors but I guess I can always add in another graphics card if not.
>>>>>

>>>>> Reason I am looking at these is that I absolutely positively do not
>>>>> want
>>>>> any computer with Windows 8 in here and unfortunately that's what many
>>>>> others come with.
>>>>

>>>> I have spent too many hours this weekend tweaking the transient
>>>> response of a semi-hysteretic (we call it "hysterical") switchmode
>>>> constant-current source. There are about 8 interacting knobs to turn.
>>>> At 30 seconds per run, understanding the interactions is impossible.
>>>>

>>>> I want sliders on each of the part values, and I want to see the
>>>> waveforms change as I move the sliders, like they were trimpots on a
>>>> breadboard and I was looking at a scope. I need maybe 500 times the
>>>> compute power that I have now.
>>>>
>>>> Mike should code LT Spice to execute on a high-end video card.
>>>>
>>>>
>>>

>>> You can go quite a bit faster with a nice multicore machine--LTspice
>>> lets you choose how many threads to run. My desktop machine (about 3
>>> years old now) runs about 150 Gflops peak. Supermicro is an excellent
>>> vendor.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> There's a setting for one or two threads. Is that all?
>>
>>
> That's because you only have two cores. Mine goes up to 15.

16 actually. Here's a picture:
http://electrooptical.net/pictures/LTspice16threads.png

Cheers

Phil Hobbs
>
> Cheers
>
> Phil Hobbs
>


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

[Martin Brown]

On 03/11/2014 04:04, miso wrote:

> I'm on a quad core Xeon, which means I can have 8 threads. Also a Supermicro
> motherboard with 32G of error correcting RAM. Basically a low end
> workstation.
>
> LT Spice has been multithreaded for about 5 years now, but the nature of
> spice simulation won't lead to a linear speed up with the number of cores.
> In fact, your setting of three makes sense based on system monitor analysis.

The more interesting question is whether the i7 with 4 cores and
hyperthreading to run 8 threads actually provides any better performance
with LTSpice than the corresponding i5 with 4 real cores and no
hyperthreading. Sometimes 5 or 6 threads is optimum but quite often in
search problems it consumes power without speeding it up!

In some chess problems the i5 can be faster and certainly cheaper!

Be interested to know if it holds with LTSpice too.

--
Regards,
Martin Brown

[John Larkin]

On Mon, 03 Nov 2014 01:43:29 -0800, miso <mi...@sushi.com> wrote:

>John Larkin wrote:
>
>>>Spice is not a design tool. It is a verification tool.
>>>
>>>
>>
>> Of course it's a design tool. Why spend a half hour cranking out a
>> voltage divider network with a calculator, when you can Spice and
>> fiddle a solution in a few minutes?
>>
>> Is a calculator a design tool? Is an equation a design tool?
>>
>>
>
>A voltage divider. We're talking Ohm's law here. You would really resort to
>Spice to design something that can be done simply with middle school
>algebra?

If it saves me time, absolutely.

>
>Have I used Spice to analyze a resistor divider? Actually yes, but in finite
>element analysis to simulate a laser trim procedure. The basic networks are
>designed by hand.

Do that if you enjoy it. I'd rather get scut work like that over as
soon as possible, which is often Spice + twiddle.

Here's a divide-and-offset network designed by fiddling. The object
was to map +-10.5 volts or so into the unipolar ADC range with
available parts, already on the BOM. The final close-enough in:out
transfer function was determined by Spice, then plugged into the ARM
code... the opposite of the classic design direction. A bonus is that
the .asc file is part of the permanent design record, and easily
revisited if ever necessary.

This took minutes.

Version 4
SHEET 1 880 680
WIRE 224 -16 112 -16
WIRE 112 16 112 -16
WIRE 224 64 224 -16
WIRE 112 128 112 96
WIRE -192 192 -256 192
WIRE -48 192 -112 192
WIRE 0 192 -48 192
WIRE 48 192 0 192
WIRE 224 192 224 144
WIRE 224 192 128 192
WIRE 400 192 224 192
WIRE 448 192 400 192
WIRE -256 240 -256 192
WIRE 224 240 224 192
WIRE -48 256 -48 192
WIRE -256 368 -256 320
WIRE -48 368 -48 336
WIRE 224 368 224 320
FLAG -256 368 0
FLAG 224 368 0
FLAG 112 128 0
FLAG -48 368 0
FLAG 400 192 ADC
FLAG 0 192 IN
SYMBOL res 208 48 R0
WINDOW 0 60 44 Left 2
WINDOW 3 60 79 Left 2
SYMATTR InstName R1
SYMATTR Value 1K
SYMBOL res 208 224 R0
WINDOW 0 50 37 Left 2
WINDOW 3 51 71 Left 2
SYMATTR InstName R2
SYMATTR Value 1K
SYMBOL res 144 176 R90
WINDOW 0 67 56 VBottom 2
WINDOW 3 73 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 2K
SYMBOL voltage -256 224 R0
WINDOW 0 55 68 Left 2
WINDOW 3 39 109 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 10.15
SYMBOL voltage 112 0 R0
WINDOW 0 -80 43 Left 2
WINDOW 3 -73 81 Left 2
SYMATTR InstName V2
SYMATTR Value 3
SYMBOL res -64 240 R0
WINDOW 0 51 44 Left 2
WINDOW 3 52 75 Left 2
SYMATTR InstName R5
SYMATTR Value 50
SYMBOL res -96 176 R90
WINDOW 0 -51 49 VBottom 2
WINDOW 3 -37 49 VTop 2
SYMATTR InstName R6
SYMATTR Value 50
TEXT 280 -8 Left 2 ;PIEZO DIVIDER FOR Z354 TEST BOARD
TEXT 376 40 Left 2 ;JL JULY 30 2014
TEXT 352 240 Left 2 ;ARM ADC RANGE IS 0 TO +3
TEXT 488 136 Left 2 !;tran 3
TEXT 344 280 Left 2 ;PIEZO DAC RANGE +-10.15V
TEXT 504 104 Left 2 !.op

[DecadentLinuxUserNumeroUno]

On Mon, 03 Nov 2014 13:14:47 +0000, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> Gave us:

>In some chess problems the i5 can be faster and certainly cheaper!

Bullshit.

[Martin Brown]

You demonstrate clearly that you are an inarticulate moron.
Why am I not surprised?

It is easy enough to do the tests and see for yourself. Hyperthreading
can get in the way of fast multithreading in some larger problems.

--
Regards,
Martin Brown

[DecadentLinuxUserNumeroUno]

On Mon, 03 Nov 2014 16:48:29 +0000, Martin Brown

<|||newspam|||@nezumi.demon.co.uk> Gave us:

>On 03/11/2014 16:26, DecadentLinuxUserNumeroUno wrote:
>> On Mon, 03 Nov 2014 13:14:47 +0000, Martin Brown
>> <|||newspam|||@nezumi.demon.co.uk> Gave us:
>>
>>> In some chess problems the i5 can be faster and certainly cheaper!
>>
>> Bullshit.
>
>You demonstrate clearly that you are an inarticulate moron.
>Why am I not surprised?
>
>It is easy enough to do the tests and see for yourself. Hyperthreading
>can get in the way of fast multithreading in some larger problems.

Again.. you spout crap, but have no clue about actual operation or
function.

I can turn OFF HT in my Motherboard BIOS setup.

I will bet you that your chess app runs the same in both settings, if
the code never uses it.

So, no... it typically NEVER "gets in the way", and YOU need to cite
a condition where it does, not merely spout off horseshit as if you are
a fucking professor.

Your brain benchmark takes a big hit when you pull this stupid
guesswork bullshit.

[Kevin Aylward]

"John Larkin" wrote in message
news:0nkc5aljhec5r36pt...@4ax.com...

>I have spent too many hours this weekend tweaking the transient
>response of a semi-hysteretic (we call it "hysterical") switchmode
>constant-current source. There are about 8 interacting knobs to turn.
>At 30 seconds per run, understanding the interactions is impossible.

Only 30 seconds, Luxury. A large bulk of my sims at work are in the 15 mins
to 1 hour range, some take overnight.

>I want sliders on each of the part values, and I want to see the
>waveforms change as I move the sliders, like they were trimpots on a
>breadboard and I was looking at a scope. I need maybe 500 times the
>>compute power that I have now.

It doesn't look like you need core compute power to me, you want a spice
with real time control of components for this particular method of, er..
ahmmm.. "pissing" about design approach.

You can actually do this in SS. If real time mode is enabled, with marching
waveforms also enabled, changing component like resistors and caps will
update the simulation matrix immediately and the marching waveform will
reflect this. There are other spice programs out there that are better
designed for real time technician twiddling though.

The er...hmmm.. more professional way is to set up multi way sweeps of all
the pots you want to twiddle, and examine the resulting set of graphs. You
can gain intuition by doing this, even after the fact. That's what those
that generate millions of asic chips do anyway.

:-)

Kevin Aylward
www.kevinaylward.co.uk
www.anasoft.co.uk - SuperSpice

[Joerg]

Lasse Langwadt Christensen wrote:

> Den søndag den 2. november 2014 18.24.23 UTC+1 skrev Joerg:
>> Joerg wrote:
>>> Carl Ijames wrote:
>>>> Don't know about computation speed, but this link says the video card will
>>>> drive 3 monitors:
>>>> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/specifications.
>>>> Looking at Dell's site I don't see any mention of expansion slots, and
>>>> looking at the one picture with the cover off I really can't see any sockets
>>>> beyond the video card, so if any further expansion is important you need to
>>>> ask Dell for clarification.
>>>>
>>> Looks like you are right:
>>>
>>> http://www.dell.com/ed/business/p/xps-8700/pd
>>> http://core0.staticworld.net/images/article/2013/07/1253541_sr-1160-100047019-orig.jpg
>>> http://www.pcworld.com/article/2047487/dell-xps-8700-special-editions-review-a-little-less-performance-for-a-lot-less-cash.html
>>>
>>> Quote "There's only one PCIe x16 slot, which means you won't be able to
>>> add a second video card to take advantage of Nvidia's SLI technology".
>>>
>>> No slots. There's one more card in the bottom, not sure what that is.
>>> But if the video can drive three monitors it should be fine, I never
>>> added any cards to my current PC either.
>>>

>> Only question is, how can one connect two regular OPC monitors to this?
>>
>> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-images
>>
>

> I'd expect that you can connect a monitor to each of the three outputs,
> VGA,DVI,HDMI. I have an old geforce and that's how that works
>
> VGA is not much use, but unless you want to watch something from Hollywood
> DVI and HDMI is the same thing
>

I do a lot of video conferencing via web where content moves. Other than
that just CAD, no movie streaming and such.

--
Regards, Joerg

http://www.analogconsultants.com/

[Joerg]

Phil Hobbs wrote:

> On 11/2/2014 12:31 PM, Joerg wrote:
>> Phil Hobbs wrote:
>>> On 11/2/2014 11:00 AM, John Larkin wrote:
>>>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
>>>> wrote:
>>>>
>>>>> Folks,
>>>>>
>>>>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt
>>>>> stated
>>>>> that the Intel i7 is a really good processor for LTSPice. According to
>>>>> this it looks like the 4790 is the fastest of the bunch:
>>>>>
>>>>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>>>>
>>>>>
>>>>>
>>>>> So, what do thee say, is the computer in the Costco link below a good
>>>>> deal for LTSpice purposes?
>>>>>
>>>>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>>>>
>>>>>
>>>>>
>>>>> It's also available without MS-Office Home & Student 2013 for $100
>>>>> less
>>>>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>>>>> that sounds like an ok deal. My hope is that it can drive two 27"
>>>>> monitors but I guess I can always add in another graphics card if not.
>>>>>
>>>>> Reason I am looking at these is that I absolutely positively do not
>>>>> want
>>>>> any computer with Windows 8 in here and unfortunately that's what many
>>>>> others come with.
>>>>

>>>> I have spent too many hours this weekend tweaking the transient
>>>> response of a semi-hysteretic (we call it "hysterical") switchmode
>>>> constant-current source. There are about 8 interacting knobs to turn.
>>>> At 30 seconds per run, understanding the interactions is impossible.
>>>>

>>>> I want sliders on each of the part values, and I want to see the
>>>> waveforms change as I move the sliders, like they were trimpots on a
>>>> breadboard and I was looking at a scope. I need maybe 500 times the
>>>> compute power that I have now.
>>>>

>>>> Mike should code LT Spice to execute on a high-end video card.
>>>>
>>>>
>>>
>>> You can go quite a bit faster with a nice multicore machine--LTspice
>>> lets you choose how many threads to run. My desktop machine (about 3
>>> years old now) runs about 150 Gflops peak. Supermicro is an excellent
>>> vendor.
>>>
>>

>> But they should work on their web site some more or get rid of scripting
>> or whatever. Other than a language selector it shows ... nothing.
>>
> Probably a NoScript issue, or something like that.


Why on earth can't web designers figure out the feedback thing. Like
when a script won't excecute show a warning about it.


> ... Talk to Alexander at
> alvio.com a primo Supermicro reseller, and tell him "Hi" from me.
>

Their site is a bit weird as well. On some lines you can select
components but, for example, not the version of i& processor or the monitor:

http://www.alvio.com/config.aspx?t=&product_ID=111084

[Joerg]

That's where it becomes esoteric to me. I just want to install LTSpice
and ... simulate. Not get into the business of IT and computer science
which is pretty foreign to us analog guys anyhow.

[Joerg]

Klaus Kragelund wrote:
> I have a two year old laptop. I was tired with the slow startup of
> programs, so I replaced the hard disk with a SSD. Amazing difference
> in speed. As far as I can see also for the simulations although I did
> not do a benchmark test.
>
> The Kingston SSD came with a USB connected enclosure to mount the old
> hard disk in, so the harrdisk was mirrored and no re install of
> programs was needed
>

That's what some folks in Germany said as well. Although I don't know
why because if you had a machine with, say, 32GB of RAM then everything
and the kitchen sink will comfortably fit into that much RAM and should
execute even faster than via SSD.

[Joerg]

Jeff Liebermann wrote:
> On Sun, 02 Nov 2014 09:53:42 -0800, Joerg <ne...@analogconsultants.com>
> wrote:
>
>> Any guess how long MS will support Win-7?
>
> Jan 13, 2015
> <http://windows.microsoft.com/en-us/windows/lifecycle>
> Extended support means that MS will gladly continue supporting Windoze
> 7 if you throw money at them. MS is following the Apple policy of
> killing everything that's more than 5 years old (except in California,
> which is 7 years):
> <http://support.apple.com/en-us/ht1752>
>
>> When it comes to PCs I am lazy :-)
>
> That's why I'm still in business to seperate such customers from their
> money. Lazy is good for supporting my decadent and lavish lifestyle.
>
>> I just want to plug it in and go. Re-installing all my stuff takes
>> enough time already.
>
> It's fairly easy to migrate programs and data from most anything to
> Windoze 7.
> <http://www.dummies.com/how-to/content/how-to-use-easy-transfer-in-windows-7.html>
> <http://windows.microsoft.com/en-us/windows7/products/features/windows-easy-transfer>
> However, Easy Transfer disappeared in Windoze 8.1, so you're either on
> your own or purchase a 3rd part program to do the dirty work.
>

Well, I do want to update a lot of the software to newer versions and
also I do not trsut auto-installers.

>>> Before buying anything, I suggest you try LTspice on the new machine.
>>> This is VERY easy with LTspice which doesn't use the registry or
>>> require admin rights. Just copy the files to a flash drive and it
>>> should work.

>> I am quite sure Costco will not let me do this :-)
>
> It's easier to obtain forgiveness than permission.
>
> Are you really going to spend $1,300+ for a new machine without even a
> test drive? ...


Done it before, worked every time.


> ... Costco has a very good return policy, but you still have
> to haul it home, get it running, update, tweak, tune, and then try. If
> unacceptable, you get to try and fit everything back into the original
> box (which never seems to fit). This is not being lazy.
>

Ok, but for example a gamer machine like the XPS series is a pretty good
bet that it'll perform well with SPICE.

[Joerg]

rickman wrote:

> On 11/2/2014 12:53 PM, Joerg wrote:
>> Jeff Liebermann wrote:

>>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
>>> wrote:
>>>

>>> LTspice benchmark on various machines:
>>> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>>>
>>>

>>>> Reason I am looking at these is that I absolutely positively do not
>>>> want
>>>> any computer with Windows 8 in here and unfortunately that's what many
>>>> others come with.
>>>

>>> Windoze 8.1 can be made semi-tolerable by putting the start menu back
>>> in and making it look like Windoze 7.
>>> <http://www.classicshell.net>
>>> I've been installing it on all my customers Windoze 8.1 machines and
>>> have had no complaints or problems. If you like wiggly icons on the
>>> Windoze 8.1 start screen, you can do <Shift><Start>.
>>>
>>

>> Too much risk. I've heard that running legacy software is tough in Win-8
>> but Win-7 can mostly do it. Not as good as XP.
>
> What legacy software? I have Windows 8 and I'm not having problems
> running anything I ran on my old Vista laptop.
>

Ahm, my SW goes back to the mid-80's. Unorthodox filter design,
beamfield simulators and such.

>
>> When it comes to PCs I am lazy :-)
>>

>> I just want to plug it in and go. Re-installing all my stuff takes
>> enough time already.
>

> I hear you. The big problem I had with setting up my Win 8 laptop was
> that a lot of the freeware has become burdened with ads, toolbars and
> other malware to the point I'm not willing to use it.
>

Yes, nagware is a major problem. It already was 10 years ago where it
took a lot of effort to rid the computer of that.

>
>>> Before buying anything, I suggest you try LTspice on the new machine.
>>> This is VERY easy with LTspice which doesn't use the registry or
>>> require admin rights. Just copy the files to a flash drive and it
>>> should work.
>>
>> I am quite sure Costco will not let me do this :-)
>

> You can try finding the computer salesperson in the store. They are
> limited by store policy of course, but I have met a few who were very
> willing to help as best they could.
>

They only have them online.

>
>>> One catch. LTspice saves its preferences to:
>>> C:\windows\scad3.ini
>>> which has to be writeable. The fix is to use the
>>> -ini <path>
>>> command line switch, which will:
>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>
> I need to note this somewhere. Writing to the Windows directory is a

> *very* bad idea. I can't tell you how many developers do all sorts of

> things they aren't supposed to under windows. That is the actual cause
> of many problems people have running older software under Windows. They
> don't listen to the people providing them with the OS!
>

I install everything in my own directory called "Programs". That avoids
a lot of such issues. Makes it tough in a multi-user environment but I
work alone here.

[Lasse Langwadt Christensen]

Then DVI will works just fine, HDMI is just DVI with optional audio and the encryption Hollywood insists on if you bought a blueray movie

So just plug a monitor into both the HDMI and DVI output

-Lasse

[Joerg]

rickman wrote:

> On 11/2/2014 10:25 AM, Joerg wrote:
>> Folks,
>>
>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>> that the Intel i7 is a really good processor for LTSPice. According to
>> this it looks like the 4790 is the fastest of the bunch:
>>
>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>
>>
>> So, what do thee say, is the computer in the Costco link below a good
>> deal for LTSpice purposes?
>>
>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>
>

> Hard to say. The devil is in the details. I have an i7 and I'm not
> convinced it is much better if any than other CPUs for most tasks. One
> problem with the quad core is that that each core still runs at the same
> speed as a dual core or even slower due to the contention for memory
> bandwidth. That is why I got a laptop with separate graphic memory. But
> overall I don't see big speed improvements. I'd be willing to bet you
> won't see a huge difference between this machine and one costing a few
> hundred dollars less. BTW, do you really need a new monitor? I expect
> you can save a couple hundred more by getting a unit without monitor.
>

That's just it, the price differential for the monitor is only $100.
Bought separately they are >$250. I could use it for a dual-monitor
setup. Two 27-inchers would allow me to have module spec, schematic,
layout and Digikey page in view simultaneously.

>
>> It's also available without MS-Office Home & Student 2013 for $100 less
>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>> that sounds like an ok deal. My hope is that it can drive two 27"
>> monitors but I guess I can always add in another graphics card if not.
>

> I use LibreOffice which is the same package from the developers who
> jumped ship at Oracle to continue development of OpenOffice the way they
> think is best. I don't see compatibility issues and 90% of what I use
> office for is the spreadsheet.
>

I've seen lots of issues, mostly with Excel. No VBA, x-axis in plots
gets crunched into oblivion and so on. Not too often but enough that I'd
be willing to spend the $100 for the MS-Office suite. Of course my
default Office package will be OO.

>
>> Reason I am looking at these is that I absolutely positively do not want
>> any computer with Windows 8 in here and unfortunately that's what many
>> others come with.
>

> Get something tailor made. You can get both the best machine and the
> cheapest that way. After all, they are all made from the same parts. It
> is just a question of who puts them together.
>

Got to find a local place for that. Or I could use Phil Hoobs' supplier
over the web because he said they are good.

[Joerg]

upsid...@downunder.com wrote:
> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
> wrote:
>

>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>> that the Intel i7 is a really good processor for LTSPice. According to
>> this it looks like the 4790 is the fastest of the bunch:
>>
>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>
>> So, what do thee say, is the computer in the Costco link below a good
>> deal for LTSpice purposes?
>>
>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>

> How well does LTSpice spread simulation cycles between multiple
> processors and multiple cores (Hyperthreading etc.) ?
>

Supposedly quite well but I am new to this, so I don't have any
experience. Once we did a crude benchmarking and a guy with a quad-core
ran my sim more than 3x faster. Heck, I'd plunk down money even for 1.5x.

[Joerg]

DecadentLinuxUserNumeroUno wrote:
> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>

> Gave us:

>
>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>> that the Intel i7 is a really good processor for LTSPice. According to
>> this it looks like the 4790 is the fastest of the bunch:
>>
>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>

> That actually looks like a really nice deal. You can't go wrong.


Thanks, good to know.


> Mine cost me $2500 and took over a year to build as budgets tightened.
>
> I'll bet my 3930K beats it though.
>
> The newer fabs have higher GHz rates, but are not as fast as their
> first series were, which the smaller fabs replaced..
>
> I have 6x2 cores, and I don't even know if they do that any more
> except on Xeons.
>
> I scream past all the benchmarks. Two more cores really makes a
> difference. I beat machines pegging faster raw "speeds" all the time.
> Mainly because they only have 4x2 cores.
>
> Not cheap. The i7-3930K was $695, and the X79 Mobo under it was $400.
> The 32GB RAM was not cheap either for 2133MHz, And that was before the
> 2400MHz stuff appeared. I can still upgrade the GPU and the RAM and get
> even faster.
>

The Costco machines have 1600MHz RAM so that might put a slight crimp
into things.


> Since I cannot afford to put $1000 into a Titan video card, I miss on
> a few benchmarks with my $250 GTX650.


I am not at all concerned about video because that's just used for
static display and sometimes video conferencing. No games, no movies.

[rickman]

On 11/3/2014 11:54 AM, DecadentLinuxUserNumeroUno wrote:
> On Mon, 03 Nov 2014 16:48:29 +0000, Martin Brown
> <|||newspam|||@nezumi.demon.co.uk> Gave us:
>
>> On 03/11/2014 16:26, DecadentLinuxUserNumeroUno wrote:
>>> On Mon, 03 Nov 2014 13:14:47 +0000, Martin Brown
>>> <|||newspam|||@nezumi.demon.co.uk> Gave us:
>>>
>>>> In some chess problems the i5 can be faster and certainly cheaper!
>>>
>>> Bullshit.
>>
>> You demonstrate clearly that you are an inarticulate moron.
>> Why am I not surprised?
>>
>> It is easy enough to do the tests and see for yourself. Hyperthreading
>> can get in the way of fast multithreading in some larger problems.
>
> Again.. you spout crap, but have no clue about actual operation or
> function.
>
> I can turn OFF HT in my Motherboard BIOS setup.
>
> I will bet you that your chess app runs the same in both settings, if
> the code never uses it.

Hyperthreading runs two threads on one processor taking advantage of
unused execution resources to allow one thread to run when the other
thread is stalled. But the memory bandwidth is still limited and
contention for this resource can cause more delay than the second thread
provides a gain.

If you would care to do a little digging for info on this I'm sure you
can find something that will help you learn.

"Overall the performance history of hyper-threading was a mixed one in
the beginning. As one commentary on high performance computing from
November 2002 notes:

Hyper-Threading can improve the performance of some MPI
applications, but not all. Depending on the cluster configuration and,
most importantly, the nature of the application running on the cluster,
performance gains can vary or even be negative. The next step is to use
performance tools to understand what areas contribute to performance
gains and what areas contribute to performance degradation.[12]"

Guess where I found this...

--

Rick

[rickman]

I have no idea what you are talking about. 32 GB of RAM is great as
RAM, but how does it mitigate the speed problems of a rotating hard
drive? When you run spice, where does your simulation data get saved?

--

Rick

[Joerg]

Ok, but can one be sure that an ordinary cheap 27" 1920*1080 monitor
will plug into either of them? For example, the ViewSonic VA2702w I have
here only has the large DVI connector, not the narrow HDMI. It does have
VGA though which I am using right now (good enough for my purposes).

[rickman]

On 11/3/2014 3:41 PM, Joerg wrote:
> rickman wrote:
>> On 11/2/2014 12:53 PM, Joerg wrote:
>>> Jeff Liebermann wrote:
>>>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>
>>>> wrote:
>>>>
>>>> LTspice benchmark on various machines:
>>>> <http://fetting.se/images/PC%20Speed%20Benchmark%20running%20LTspice%20circuits.pdf>
>>>>
>>>>
>>>>> Reason I am looking at these is that I absolutely positively do not
>>>>> want
>>>>> any computer with Windows 8 in here and unfortunately that's what many
>>>>> others come with.
>>>>
>>>> Windoze 8.1 can be made semi-tolerable by putting the start menu back
>>>> in and making it look like Windoze 7.
>>>> <http://www.classicshell.net>
>>>> I've been installing it on all my customers Windoze 8.1 machines and
>>>> have had no complaints or problems. If you like wiggly icons on the
>>>> Windoze 8.1 start screen, you can do <Shift><Start>.
>>>>
>>>
>>> Too much risk. I've heard that running legacy software is tough in Win-8
>>> but Win-7 can mostly do it. Not as good as XP.
>>
>> What legacy software? I have Windows 8 and I'm not having problems
>> running anything I ran on my old Vista laptop.
>>
>
> Ahm, my SW goes back to the mid-80's. Unorthodox filter design,
> beamfield simulators and such.

So DOS programs? What makes you think they won't work under Win8? The
usual FUD?

>>> When it comes to PCs I am lazy :-)
>>>
>>> I just want to plug it in and go. Re-installing all my stuff takes
>>> enough time already.
>>
>> I hear you. The big problem I had with setting up my Win 8 laptop was
>> that a lot of the freeware has become burdened with ads, toolbars and
>> other malware to the point I'm not willing to use it.
>>
>
> Yes, nagware is a major problem. It already was 10 years ago where it
> took a lot of effort to rid the computer of that.
>
>>
>>>> Before buying anything, I suggest you try LTspice on the new machine.
>>>> This is VERY easy with LTspice which doesn't use the registry or
>>>> require admin rights. Just copy the files to a flash drive and it
>>>> should work.
>>>
>>> I am quite sure Costco will not let me do this :-)
>>
>> You can try finding the computer salesperson in the store. They are
>> limited by store policy of course, but I have met a few who were very
>> willing to help as best they could.
>>
>
> They only have them online.

I've never been a fan of Costco for computers, with one exception. They
let you return a computer, no questions asked for 90 days I believe. So
you can try it out at home.

>>>> One catch. LTspice saves its preferences to:
>>>> C:\windows\scad3.ini
>>>> which has to be writeable. The fix is to use the
>>>> -ini <path>
>>>> command line switch, which will:
>>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>>
>> I need to note this somewhere. Writing to the Windows directory is a
>> *very* bad idea. I can't tell you how many developers do all sorts of
>> things they aren't supposed to under windows. That is the actual cause
>> of many problems people have running older software under Windows. They
>> don't listen to the people providing them with the OS!
>>
>
> I install everything in my own directory called "Programs". That avoids
> a lot of such issues. Makes it tough in a multi-user environment but I
> work alone here.

That helps one aspect, the nags from the OS about writing data. But you
have lost the benefit of the Program Files directory being protected.
It makes your executables that much easier to infect, although that is
not typically a problem since good AVS stops malware long before it gets
a chance to infect the hard drive.

--

Rick

[Joerg]

Normally on the HD. But not in the DOS days, there I used (part of) an
extra 4MB that I installed for this. RAM-disk should also be possible
under Windows. Like here:

http://blog.laptopmag.com/faster-than-an-ssd-how-to-turn-extra-memory-into-a-ram-disk

[Lasse Langwadt Christensen]

yes, for regular computer monitor HDMI and DVI is the same thing, you just
need the right cable or a adapter to get the wires in the right holes ;)

-Lasse

[rickman]

On 11/3/2014 3:47 PM, Joerg wrote:
> rickman wrote:
>> On 11/2/2014 10:25 AM, Joerg wrote:
>>> Folks,
>>>
>>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated
>>> that the Intel i7 is a really good processor for LTSPice. According to
>>> this it looks like the 4790 is the fastest of the bunch:
>>>
>>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>>
>>>
>>> So, what do thee say, is the computer in the Costco link below a good
>>> deal for LTSpice purposes?
>>>
>>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>>
>>
>> Hard to say. The devil is in the details. I have an i7 and I'm not
>> convinced it is much better if any than other CPUs for most tasks. One
>> problem with the quad core is that that each core still runs at the same
>> speed as a dual core or even slower due to the contention for memory
>> bandwidth. That is why I got a laptop with separate graphic memory. But
>> overall I don't see big speed improvements. I'd be willing to bet you
>> won't see a huge difference between this machine and one costing a few
>> hundred dollars less. BTW, do you really need a new monitor? I expect
>> you can save a couple hundred more by getting a unit without monitor.
>>
>
> That's just it, the price differential for the monitor is only $100.
> Bought separately they are >$250. I could use it for a dual-monitor
> setup. Two 27-inchers would allow me to have module spec, schematic,
> layout and Digikey page in view simultaneously.

Heck, for $100 that's a good deal.

>>> It's also available without MS-Office Home & Student 2013 for $100 less
>>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>>> that sounds like an ok deal. My hope is that it can drive two 27"
>>> monitors but I guess I can always add in another graphics card if not.
>>
>> I use LibreOffice which is the same package from the developers who
>> jumped ship at Oracle to continue development of OpenOffice the way they
>> think is best. I don't see compatibility issues and 90% of what I use
>> office for is the spreadsheet.
>>
>
> I've seen lots of issues, mostly with Excel. No VBA, x-axis in plots
> gets crunched into oblivion and so on. Not too often but enough that I'd
> be willing to spend the $100 for the MS-Office suite. Of course my
> default Office package will be OO.

The only issue I've seen is when I add block diagrams to a spreadsheet.
Seems LO likes to shove it all up into the upper left corner
sometimes. I've never had trouble with any graphs, although I can't
figure out how to add engineering notation to LO or a third Y axis for
plotting multiple types of data on one plot. Can you do that in OO or
Excel?

>>> Reason I am looking at these is that I absolutely positively do not want
>>> any computer with Windows 8 in here and unfortunately that's what many
>>> others come with.
>>
>> Get something tailor made. You can get both the best machine and the
>> cheapest that way. After all, they are all made from the same parts. It
>> is just a question of who puts them together.
>>
>
> Got to find a local place for that. Or I could use Phil Hoobs' supplier
> over the web because he said they are good.

Most custom shops will be good because if they aren't, they are gone.
Word of mouth is a *big* deal with these sort of shops.

--

Rick

[rickman]

If you are going for power, you need to have separate video memory or
the video eats memory bandwidth which is often the limiting factor on a
multicore machine.

I haven't kept up with the hotrod machines these days, but I'd be
willing to bet you will get a lot better performance with multi-banked
RAM. Does this machine have two or more memory interfaces or just one?

--

Rick

[Joerg]

So then here in the photo the center one is HDMI and the right one is
DVI and that's where the two monitors should go to? I could also hook
one up to VGA like I have now.

http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-images

Says dual-link or DVI-D for the DVI connector in the specs, whatever
that means.

[Joerg]

Yup :-)

>
>>>> It's also available without MS-Office Home & Student 2013 for $100 less
>>>> but I found that OpenOffice isn't 100% compatible in the Excel area so
>>>> that sounds like an ok deal. My hope is that it can drive two 27"
>>>> monitors but I guess I can always add in another graphics card if not.
>>>
>>> I use LibreOffice which is the same package from the developers who
>>> jumped ship at Oracle to continue development of OpenOffice the way they
>>> think is best. I don't see compatibility issues and 90% of what I use
>>> office for is the spreadsheet.
>>>
>>
>> I've seen lots of issues, mostly with Excel. No VBA, x-axis in plots
>> gets crunched into oblivion and so on. Not too often but enough that I'd
>> be willing to spend the $100 for the MS-Office suite. Of course my
>> default Office package will be OO.
>
> The only issue I've seen is when I add block diagrams to a spreadsheet.
> Seems LO likes to shove it all up into the upper left corner
> sometimes. I've never had trouble with any graphs, although I can't
> figure out how to add engineering notation to LO or a third Y axis for
> plotting multiple types of data on one plot. Can you do that in OO or
> Excel?
>

No idea, I am always at the receiving end. Clients send me Excel plots
of test data logged with stuff that I designed and then it's "Oh, I
can't read some of it". When I open it on a computer that has genuine
MS-Office it works but I do not have enough licenses for all computers.

>
>>>> Reason I am looking at these is that I absolutely positively do not
>>>> want
>>>> any computer with Windows 8 in here and unfortunately that's what many
>>>> others come with.
>>>
>>> Get something tailor made. You can get both the best machine and the
>>> cheapest that way. After all, they are all made from the same parts. It
>>> is just a question of who puts them together.
>>>
>>
>> Got to find a local place for that. Or I could use Phil Hoobs' supplier
>> over the web because he said they are good.
>
> Most custom shops will be good because if they aren't, they are gone.
> Word of mouth is a *big* deal with these sort of shops.
>

True. But when it comes to contemporary PCs I am a newbie, so I wouldn't
even know what to look for and PC assemblers don't know anything about
network simulation.

It's like going into Bel Air. My wife knows exactly what to pick for the
ingredients of a meal. Me? I'd be lost, except in the beer aisle. But
plop me down in a restaurant and within milliseconds I know what I'd
like to eat.

[Lasse Langwadt Christensen]

yes, you can hook up three monitors

>
> http://www.geforce.com/hardware/desktop-gpus/geforce-gt-720/product-images
>
> Says dual-link or DVI-D for the DVI connector in the specs, whatever
> that means.
>

single-link is three differential pairs, dual-link has three extra pairs that are used for the higher bandwidth need for very high resolutions

afair single link DVI is limited to 1920x1200 at 60 Hz


-Lasse

[Joerg]

rickman wrote:
> On 11/3/2014 3:51 PM, Joerg wrote:
>> DecadentLinuxUserNumeroUno wrote:

[...]

>>> Since I cannot afford to put $1000 into a Titan video card, I miss on
>>> a few benchmarks with my $250 GTX650.
>>
>>
>> I am not at all concerned about video because that's just used for
>> static display and sometimes video conferencing. No games, no movies.
>
> If you are going for power, you need to have separate video memory or
> the video eats memory bandwidth which is often the limiting factor on a
> multicore machine.
>
> I haven't kept up with the hotrod machines these days, but I'd be
> willing to bet you will get a lot better performance with multi-banked
> RAM. Does this machine have two or more memory interfaces or just one?
>

No clue. But with SPICE the graphics action is very slow, just a wee
progress of a few traces on an otherwise static screen. And you could
even turn that off.

[Joerg]

Thanks. 1920*1080 at 60Hz would be all I need.

[Joerg]

Phil Hobbs wrote:
> On 11/02/2014 01:17 PM, Phil Hobbs wrote:
>> On 11/2/2014 12:45 PM, John Larkin wrote:
>>> On Sun, 02 Nov 2014 11:06:30 -0500, Phil Hobbs
>>> <ho...@electrooptical.net> wrote:

>>>
>>>> On 11/2/2014 11:00 AM, John Larkin wrote:
>>>>> On Sun, 02 Nov 2014 07:25:49 -0800, Joerg <ne...@analogconsultants.com>

>>>>> wrote:
>>>>>
>>>>>> Folks,
>>>>>>
>>>>>> Need to spiff up my simulation speeds here. IIRC Mike Engelhardt
>>>>>> stated
>>>>>> that the Intel i7 is a really good processor for LTSPice.
>>>>>> According to
>>>>>> this it looks like the 4790 is the fastest of the bunch:
>>>>>>
>>>>>> http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html
>>>>>>
>>>>>>
>>>>>>
>>>>>> So, what do thee say, is the computer in the Costco link below a good
>>>>>> deal for LTSpice purposes?
>>>>>>
>>>>>> http://www.costco.com/Dell-XPS-8700-Desktop-%7c-Intel-Core-i7-%7c-1GB-Graphics-%7c-Windows-7-Professional.product.100131208.html
>>>>>>
>>>>>>
>>>>>>

>>>>>> It's also available without MS-Office Home & Student 2013 for $100
>>>>>> less
>>>>>> but I found that OpenOffice isn't 100% compatible in the Excel
>>>>>> area so
>>>>>> that sounds like an ok deal. My hope is that it can drive two 27"
>>>>>> monitors but I guess I can always add in another graphics card if
>>>>>> not.
>>>>>>

>>>>>> Reason I am looking at these is that I absolutely positively do not
>>>>>> want
>>>>>> any computer with Windows 8 in here and unfortunately that's what
>>>>>> many
>>>>>> others come with.
>>>>>

>>>>> I have spent too many hours this weekend tweaking the transient
>>>>> response of a semi-hysteretic (we call it "hysterical") switchmode
>>>>> constant-current source. There are about 8 interacting knobs to turn.
>>>>> At 30 seconds per run, understanding the interactions is impossible.
>>>>>
>>>>> I want sliders on each of the part values, and I want to see the
>>>>> waveforms change as I move the sliders, like they were trimpots on a
>>>>> breadboard and I was looking at a scope. I need maybe 500 times the
>>>>> compute power that I have now.
>>>>>
>>>>> Mike should code LT Spice to execute on a high-end video card.
>>>>>
>>>>>
>>>>
>>>> You can go quite a bit faster with a nice multicore machine--LTspice
>>>> lets you choose how many threads to run. My desktop machine (about 3
>>>> years old now) runs about 150 Gflops peak. Supermicro is an excellent
>>>> vendor.
>>>>

>>>> Cheers
>>>>
>>>> Phil Hobbs
>>>
>>> There's a setting for one or two threads. Is that all?
>>>
>>>
>> That's because you only have two cores. Mine goes up to 15.
>
> 16 actually. Here's a picture:
> http://electrooptical.net/pictures/LTspice16threads.png
>

That sounds like a high-testosterone machine of a computer :-)

Which processors is in there?

[Joerg]

I've read that many DOS and also Windows 16-bit programs no longer run.

>
>>>> When it comes to PCs I am lazy :-)
>>>>
>>>> I just want to plug it in and go. Re-installing all my stuff takes
>>>> enough time already.
>>>
>>> I hear you. The big problem I had with setting up my Win 8 laptop was
>>> that a lot of the freeware has become burdened with ads, toolbars and
>>> other malware to the point I'm not willing to use it.
>>>
>>
>> Yes, nagware is a major problem. It already was 10 years ago where it
>> took a lot of effort to rid the computer of that.
>>
>>>
>>>>> Before buying anything, I suggest you try LTspice on the new machine.
>>>>> This is VERY easy with LTspice which doesn't use the registry or
>>>>> require admin rights. Just copy the files to a flash drive and it
>>>>> should work.
>>>>
>>>> I am quite sure Costco will not let me do this :-)
>>>
>>> You can try finding the computer salesperson in the store. They are
>>> limited by store policy of course, but I have met a few who were very
>>> willing to help as best they could.
>>>
>>
>> They only have them online.
>
> I've never been a fan of Costco for computers, with one exception. They
> let you return a computer, no questions asked for 90 days I believe. So
> you can try it out at home.
>

Yep. And all I have to try is LTSpice, the rest will work.

>
>>>>> One catch. LTspice saves its preferences to:
>>>>> C:\windows\scad3.ini
>>>>> which has to be writeable. The fix is to use the
>>>>> -ini <path>
>>>>> command line switch, which will:
>>>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>>>
>>> I need to note this somewhere. Writing to the Windows directory is a
>>> *very* bad idea. I can't tell you how many developers do all sorts of
>>> things they aren't supposed to under windows. That is the actual cause
>>> of many problems people have running older software under Windows. They
>>> don't listen to the people providing them with the OS!
>>>
>>
>> I install everything in my own directory called "Programs". That avoids
>> a lot of such issues. Makes it tough in a multi-user environment but I
>> work alone here.
>
> That helps one aspect, the nags from the OS about writing data. But you
> have lost the benefit of the Program Files directory being protected. It
> makes your executables that much easier to infect, although that is not
> typically a problem since good AVS stops malware long before it gets a
> chance to infect the hard drive.
>

I never had that happen. Plus the SW I run is mostly not mainstream and
should be very low on the hit list of hackers.

[rickman]

On 11/3/2014 4:28 PM, Joerg wrote:

You aren't grasping the concept. Video memory needs a sizable bandwidth
to *display* the image to the screen. All the data that goes out over
your HDMI cable is being read from memory *all the time*. You're a
bright boy. Do the math... 1920*1080*60 times 3 or 4 bytes per pixel.

This has *nothing* to do with drawing the images into graphic memory.

The memory bank question will likely be more important than the number
of cores in the CPU. The guy who can run 16 threads has at least two
memory interfaces or it would be bogging down between 4 and 8 cores.

--

Rick

[Joerg]

Jeff Liebermann wrote:

> On Sun, 02 Nov 2014 14:56:04 -0500, rickman <gnu...@gmail.com> wrote:
>
>> On 11/2/2014 12:53 PM, Joerg wrote:
>>> Too much risk. I've heard that running legacy software is tough in Win-8
>>> but Win-7 can mostly do it. Not as good as XP.
>
>> What legacy software? I have Windows 8 and I'm not having problems
>> running anything I ran on my old Vista laptop.
>

> I recently awarded myself a short vacation in honor my burning a huge
> amount of time getting old software to run nicely on Windoze 8.1.
> Specifically, the DOS versions of various fiduciary programs dating
> 1996 through 2002, which the customer insisted had to run even though
> later versions worked just fine. The problem was that the tax rules
> and tables all changed over the years and they wanted the original
> versions. I ended up running them under DOSbox, which was originally
> designed to run ancient games, but works equally well with ancient
> business applications:
> <http://www.dosbox.com/status.php?show_status=1>
> I also tried them under VMware and VirtualBox, both of which worked
> nicely, but DOSbox is easier and faster.
>
> Another horror was Office 2003 on Windoze 8.1. It installs, updates,
> loads, and looks like it might work, but eventually crashes. All I
> really needed was Outlook 2003, but that would hang after polling for
> mail a few times. I probably could have figured out the problem, but
> convinced the customer that Mozilla Thunderbird would be a suitable
> option.
>
> Then, there's WordPerfect 12 which I think was introduced in 2002.
> Amazingly, it worked 99%. However, the 1% was fatal. Windoze file
> association would not start WP12 if I double clicked on a WPD file (or
> any of the other WP files). It took a while to figure out that WP12
> was trying to use an ancient ODBC version, which required that WP12
> beg permission of the Windoze security abomination before it would
> condescend to even supply an error message. Fixed by running WP12 as
> administrator, which by passes most of the security mess.
>
> I guess the moral here is to not try to run 12+ year old software on
> Windoze 8.1. My mistake was assuming that since all the
> aforementioned software ran just fine in Windoze 7, the new and
> improved Windoze 8.1 couldn't possibly break something that already
> worked so well.


That kind of stuff cinches it for me: It has to be Win-7.

[...]

[DecadentLinuxUserNumeroUno]

On Mon, 03 Nov 2014 15:53:13 -0500, rickman <gnu...@gmail.com> Gave us:

>
>If you would care to do a little digging for info on this I'm sure you
>can find something that will help you learn.

What part of "can be turned off in the BIOS" did you not understand?

I know full well what it is.

I also know that YOU do not know what is going on, regardless of what
you read, and are happy to paste iterate back into here, appearing as if
to be a professor on the subject. You make me laugh.

We are talking about basic grasp here.

Nothing will help you learn, old man. You are hard wired stupid.

[DecadentLinuxUserNumeroUno]

On Mon, 03 Nov 2014 16:01:39 -0500, rickman <gnu...@gmail.com> Gave us:

>So DOS programs? What makes you think they won't work under Win8? The
>usual FUD?

So, you really know nothing about actual attachment to real hardware
hooks then, eh, dingledorf?

You ain't real bright, boy.

[Lasse Langwadt Christensen]

Den mandag den 3. november 2014 22.42.14 UTC+1 skrev rickman:
> On 11/3/2014 4:28 PM, Joerg wrote:
> > rickman wrote:
> >> On 11/3/2014 3:51 PM, Joerg wrote:
> >>> DecadentLinuxUserNumeroUno wrote:
> >
> > [...]
> >
> >>>> Since I cannot afford to put $1000 into a Titan video card, I miss on
> >>>> a few benchmarks with my $250 GTX650.
> >>>
> >>>
> >>> I am not at all concerned about video because that's just used for
> >>> static display and sometimes video conferencing. No games, no movies.
> >>
> >> If you are going for power, you need to have separate video memory or
> >> the video eats memory bandwidth which is often the limiting factor on a
> >> multicore machine.
> >>
> >> I haven't kept up with the hotrod machines these days, but I'd be
> >> willing to bet you will get a lot better performance with multi-banked
> >> RAM. Does this machine have two or more memory interfaces or just one?
> >>
> >
> > No clue. But with SPICE the graphics action is very slow, just a wee
> > progress of a few traces on an otherwise static screen. And you could
> > even turn that off.
>
> You aren't grasping the concept. Video memory needs a sizable bandwidth
> to *display* the image to the screen. All the data that goes out over
> your HDMI cable is being read from memory *all the time*. You're a
> bright boy. Do the math... 1920*1080*60 times 3 or 4 bytes per pixel.
>

with anything but a graphics-card integrated in the chipset that memory
will be on the card itself, 1920*1080*24bit is less that 7MB

-Lasse

[Joerg]

rickman wrote:

> On 11/2/2014 5:28 PM, Jeff Liebermann wrote:
>> On Sun, 02 Nov 2014 14:56:04 -0500, rickman <gnu...@gmail.com> wrote:
>>

>>>>> One catch. LTspice saves its preferences to:
>>>>> C:\windows\scad3.ini
>>>>> which has to be writeable. The fix is to use the
>>>>> -ini <path>
>>>>> command line switch, which will:
>>>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>>
>>> I need to note this somewhere. Writing to the Windows directory is a
>>> *very* bad idea.
>>

>> It was standard procedure in Windoze 3.1, where almost all
>> applications dropped pick_a_name.ini files in the C:\Windows\
>> directory.
>
> Yes, and Windows 3.1 crashed on a regular basis for about any reason
> whatsoever just like 95, 98 and ME.
>
> MS has been telling developers since Win2000 and maybe since NT to not
> put data files in the Windows or Program Files directories. Many chose
> to ignore this which wasn't enforced until Vista and became one of the
> things everyone loves to hate about Vista.
>

Maybe. But for us users only one thing counts: That stuff works.

>
>> I do have to admit it was handy as the files were easy to
>> find and save. The new and improved versions of Windoze hide these
>> config files in either the registry, or bury them 5 directory layers
>> deep, where few can find them without specialized tools or inside
>> information.
>
> Windows doesn't put anything from an app in the registry. That is up to
> the app to decide. Getting to these directories is easy if they used
> the right location, C:\ProgramData. Instead they continue to use
> C:\Program Files and now with Win8 MS puts the files in the long path
> name you list, but I believe they can be reached transparently through
> the path C:\Program Files So the best of both worlds.
>
> If the app puts them somewhere else, don't blame windows.
>

If it was allowed in old Windows, isn't in new Windows, and there isn't
a user selector about this then I blame Windows.

>
>>> I can't tell you how many developers do all sorts of
>>> things they aren't supposed to under windows. That is the actual cause
>>> of many problems people have running older software under Windows. They
>>> don't listen to the people providing them with the OS!
>>

>> LTspice (aka SwitcherCAD) is a rather old program, with many of the
>> traditions of Windoze 3.1 still present. If you don't like that, try
>> running some of the various NEC antenna modeling programs, that still
>> use the terms "card" and "deck" from the Hollerith punch card era. The
>> common mantra is the same everywhere... if it works, don't touch it.
>
> These programs have been updated many, many times since Windows 3.1.
> Windows NT, 2k, XP, Vista, 7, 8 and 8.1 aren't even the same OS as the
> 3.1 tree which was ended when XP was released. Stick with the old
> habits and blame yourself or your program maintainer.
>
> I use some open source Windows software that does the same crap and I am
> very vocal about the cause and the fix for the problem. Few of the
> developers are interested though. Now that 8 makes this (using Program
> Files for data) work adequately they no longer have a need to change it.
>
> If you are relying on programming habits from over 20 years ago, then
> you will have to stew in your own soup.
>

Easy to say for someone who probably never has to deal with beamfield
sims and such. Bottomline there are programs some of us have to use
where there is no alternative. Where the design teams have dissolved
decades ago and some of the folks are not with us on earth anymore. My
record so far is a chunk of software that was stored on an 8" floppy.

Software does not automatically lose its value because it is over 20
years old. Or would you pour a bottle of 1995 Domaine Leflaive
Montrachet Grand Cru [*] into the sink because it is old?

Talking about using legacy stuff, the aircraft guys are a bit more
extreme there. This aircraft is going to celebrate its 80th soon and is
used commercially:

https://www.youtube.com/watch?v=jx11k1r1Pm8

[*] It runs north of $5k. Per bottle.

[Joerg]

Well ... we did enter the 21st century. In this day and age graphics
cards come with their own memory. AFAIK the Nvidia GT720 has 1GB of on
board RAM. Others have more but that sounds sufficient. Also, there is
no need to store 60 frames if the content is more or less static.

[Martin Brown]

On 03/11/2014 20:37, Joerg wrote:

> Ok, but for example a gamer machine like the XPS series is a pretty good
> bet that it'll perform well with SPICE.

If you can persuade them to do it a gamer machine with the graphics card
entirely deleted will be the cheapest low power combo to do about what
you want. The 2D capability of the Intel graphics engine internal on the
i5 & i7 CPUs are as fast as anything on fancy 3D gaming cards.
(obviously they get totally thrashed in 3D realtime rendering tests)

Basically you can shave 100-200W of the power consumption. My i7 PC
idles at about 60W when it isn't doing anything beyond web browsing.

BTW I wouldn't waste your money on exotic faster ram unless you intend
to overclock it. Stock ram and more of it is a better price performance.

I'd be interested to see how a moderate sized LTSPice simulation scales
with the number of threads on an i5 and i7 architecture. My guess is
that hyperthreading will not be all that useful to it.

--
Regards,
Martin Brown

[Joerg]

Martin Brown wrote:
> On 03/11/2014 20:37, Joerg wrote:
>
>> Ok, but for example a gamer machine like the XPS series is a pretty good
>> bet that it'll perform well with SPICE.
>
> If you can persuade them to do it a gamer machine with the graphics card
> entirely deleted will be the cheapest low power combo to do about what
> you want. The 2D capability of the Intel graphics engine internal on the
> i5 & i7 CPUs are as fast as anything on fancy 3D gaming cards.
> (obviously they get totally thrashed in 3D realtime rendering tests)
>
> Basically you can shave 100-200W of the power consumption. My i7 PC
> idles at about 60W when it isn't doing anything beyond web browsing.
>

Problem is, unless you piece together a custom machine the ones that are
equipped with good processors and RAM up to the gills seem to always
come with these powerful graphics cards. The other issue is that
on-board graphics often will not drive two monitors. I found that out
the hard way after I bought the PC I am using now.

> BTW I wouldn't waste your money on exotic faster ram unless you intend
> to overclock it. Stock ram and more of it is a better price performance.
>

So you think 1600MHz RAM is fine?

> I'd be interested to see how a moderate sized LTSPice simulation scales
> with the number of threads on an i5 and i7 architecture. My guess is
> that hyperthreading will not be all that useful to it.
>

I am hoping the four cores will speed things up significantly. Also the
huge amount of RAM. Right now I have 2GB and I regularly hit the limit.

[Maynard A. Philbrook Jr.]

In article <01a8a0d7-a080-4ff4...@googlegroups.com>,
lang...@fonz.dk says...

how do you figure that ?

As far as I know, most video cards map a whole 32 bit per pixel for
24bit (true color) these days.

That would equate to somewhere around 67 megs I do think.

I don't know, maybe there is some compression magic I don't know
about..

Jamie

[rickman]

On 11/3/2014 5:09 PM, Joerg wrote:

> rickman wrote:
>> On 11/2/2014 5:28 PM, Jeff Liebermann wrote:
>>> On Sun, 02 Nov 2014 14:56:04 -0500, rickman <gnu...@gmail.com> wrote:
>>>
>>>>>> One catch. LTspice saves its preferences to:
>>>>>> C:\windows\scad3.ini
>>>>>> which has to be writeable. The fix is to use the
>>>>>> -ini <path>
>>>>>> command line switch, which will:
>>>>>> Specify an .ini file to use other than %WINDIR%\scad3.ini
>>>>>> <http://ltwiki.org/LTspiceHelp/LTspiceHelp/Command_Line_Switches.htm>
>>>
>>>> I need to note this somewhere. Writing to the Windows directory is a
>>>> *very* bad idea.
>>>
>>> It was standard procedure in Windoze 3.1, where almost all
>>> applications dropped pick_a_name.ini files in the C:\Windows\
>>> directory.
>>
>> Yes, and Windows 3.1 crashed on a regular basis for about any reason
>> whatsoever just like 95, 98 and ME.
>>
>> MS has been telling developers since Win2000 and maybe since NT to not
>> put data files in the Windows or Program Files directories. Many chose
>> to ignore this which wasn't enforced until Vista and became one of the
>> things everyone loves to hate about Vista.
>>
>
> Maybe. But for us users only one thing counts: That stuff works.

Do you build your stuff so that if the user connects a different
computer it craps out? No, you design your interfaces *correctly* so
that it works now and it keeps working when some peripheral piece that
should have no impact is changed out.

These developers are designing crappy software and blaming it on MS.

>>> I do have to admit it was handy as the files were easy to
>>> find and save. The new and improved versions of Windoze hide these
>>> config files in either the registry, or bury them 5 directory layers
>>> deep, where few can find them without specialized tools or inside
>>> information.
>>
>> Windows doesn't put anything from an app in the registry. That is up to
>> the app to decide. Getting to these directories is easy if they used
>> the right location, C:\ProgramData. Instead they continue to use
>> C:\Program Files and now with Win8 MS puts the files in the long path
>> name you list, but I believe they can be reached transparently through
>> the path C:\Program Files So the best of both worlds.
>>
>> If the app puts them somewhere else, don't blame windows.
>>
>
> If it was allowed in old Windows, isn't in new Windows, and there isn't
> a user selector about this then I blame Windows.

"Allowed" meaning it didn't crap out, yes. "Allowed" meaning the
developers were not designing according to best practices, no.

>>>> I can't tell you how many developers do all sorts of
>>>> things they aren't supposed to under windows. That is the actual cause
>>>> of many problems people have running older software under Windows. They
>>>> don't listen to the people providing them with the OS!
>>>
>>> LTspice (aka SwitcherCAD) is a rather old program, with many of the
>>> traditions of Windoze 3.1 still present. If you don't like that, try
>>> running some of the various NEC antenna modeling programs, that still
>>> use the terms "card" and "deck" from the Hollerith punch card era. The
>>> common mantra is the same everywhere... if it works, don't touch it.
>>
>> These programs have been updated many, many times since Windows 3.1.
>> Windows NT, 2k, XP, Vista, 7, 8 and 8.1 aren't even the same OS as the
>> 3.1 tree which was ended when XP was released. Stick with the old
>> habits and blame yourself or your program maintainer.
>>
>> I use some open source Windows software that does the same crap and I am
>> very vocal about the cause and the fix for the problem. Few of the
>> developers are interested though. Now that 8 makes this (using Program
>> Files for data) work adequately they no longer have a need to change it.
>>
>> If you are relying on programming habits from over 20 years ago, then
>> you will have to stew in your own soup.
>>
>
> Easy to say for someone who probably never has to deal with beamfield
> sims and such. Bottomline there are programs some of us have to use
> where there is no alternative. Where the design teams have dissolved
> decades ago and some of the folks are not with us on earth anymore. My
> record so far is a chunk of software that was stored on an 8" floppy.

Yeah, exactly. If you are that far back in time you man need to rethink
your approach.

> Software does not automatically lose its value because it is over 20
> years old. Or would you pour a bottle of 1995 Domaine Leflaive
> Montrachet Grand Cru [*] into the sink because it is old?

Actually software does degrade with time as you are finding out. If you
can't find a platform to run it on, it has worn out.

> Talking about using legacy stuff, the aircraft guys are a bit more
> extreme there. This aircraft is going to celebrate its 80th soon and is
> used commercially:
>
> https://www.youtube.com/watch?v=jx11k1r1Pm8
>
> [*] It runs north of $5k. Per bottle.

Good, maybe your beamfield sim will run on it. :)

--

Rick

[rickman]

It is not the amount of memory, it is the video bandwidth to keep the
monitor refreshed. Yes, it should be separate from the main memory or
you take a hit from the video accesses.

--

Rick

[Joerg]

That's megabits. In bytes this would be 8.3MB. Times two if there's two
displays. With the massive quantity of onboard memory on modern graphics
cards that is a mere drop in the bucket.

> I don't know, maybe there is some compression magic I don't know
> about..
>

No need for compression.

[rickman]

I don't know if you are playing with me or what. Yes, that is what I am
telling you, get a system with separate graphic memory which means a
separate graphics chip. Many mobos have built in video with *no* video
ram.

--

Rick

[Phil Hobbs]

It has a pair of AMD Opteron 6128s. I haven't been keeping up, but 3
years ago the Magny Cours Opterons ran rings around the Intel offerings
for floating point.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net