scsi drive speed
David Arnstein
Westly Ballard <wbal...@apollo3.com> wrote:
>I need some help with my new drive and controller card.
>
>A short while ago I purchased a Micropolis 2112s 1050 mb drive along with
>a adaptec 1542b controller card. I have it install in a 486 dx40 vlb machine
>that has 16 MB of ram and 256k cache.
>
>the problem that I am experiencing is that this machine now seems to run slower
>then my old machine which was a 386dx40 w/mathco and a Western digital 212mb
>drive. Even though the transfer rate is higher and the seek rate is lower my
>applications seem to run substancially slower. any help that you can provide will be greatly appreciated.
If you are running Microsoft Windows 3.1 or WFWG 3.11, this is to be expected.
For your pleasure, I have included a little essay on SCSI, which summarizes my
unpleasant personal experiences. I have nothing positive to say about SCSI
and Windows.
To be fair, one fellow claimed that his QLogic VL-Bus SCSI host adapter
outperformed an IDE subsystem on the same machine. Further, he claimed that he
used a reliable benchmark program: Ziff-Davis WinBench. However, he's the
only one. I'm suspicious. A lot of net.people have argued with my little
essay, but they don't supply any evidence. Either they use an unreliable
benchmark (like WinTune) or they don't even attempt to compare IDE vs. SCSI
speed on the same machine.
Anyway, here's my little essay, created out of my own bitter experience:
*** JUST SAY NO TO SCSI ***
Here's a subject that's dear to my heart. For Windows 3.1, just say
no to SCSI! More precisely, don't get SCSI unless you really need
it.
The main problem is getting Windows 32-bit disk access to work. If
you don't have 32-bit disk access, your I/O will be slow. You will
need a special Windows device driver for your SCSI host adapter
(card). As far as I know, only one vendor has these drivers: Future
Domain. And these drivers DON'T work with Windows For Work Groups
3.11.
In particular, the market leader (Adaptec) does not supply these
drivers. You pay a certain price for NOT buying Adaptec, since many
software utilities and hardware products (tape drives, scanners) are
designed to the standards defined by Adaptec.
You will have to pay about US $150.00 for a high performance SCSI
host adapter. With IDE, you will not need a high performance card to
get good performance. A SCSI drive will usually be $20 to $100 more
expensive than a very similar IDE drive.
You will end up with another BIOS (from your SCSI host adapter) in
your computer, as well as one or more DOS device drivers, and
possibly a Windows device driver. All of these gadgets take up
memory and carry the risk of an incompatibility with some other piece
of hardware or software in your machine.
If you get a bus-mastering SCSI host adapter (gives improved
performance) you will have to fiddle with it and your floppy port
tape drive (if you have one). The DMA logic used by the SCSI h.a.
and the tape drive tend to hate each other, and you will probably
have to experiment with "bus on" times.
Many users will say "I have a SCSI subsystem and it works just fine,
thank you." My point is that if your expensive SCSI hardware is
approximately as fast as your cheap, simple IDE disk, you're wasting
your money. If you don't believe that SCSI could be slow, just find
yourself a computer that has both a SCSI disk and an IDE disk. Then,
run Ziff-Davis' WinBench benchmark program to compare the speeds.
This is the benchmark program that is used in PC Magazine reviews,
it's dependable.
If you want to use a slow SCSI peripheral such as a CD-Rom drive,
consider buying a cheap SCSI host adapter just for the CD-Rom, rather
than buying an expensive h.a. and buying SCSI hard drives.
There are situations where you need SCSI. For example, it takes
extra hardware to get 3 or more IDE drives to work in the same
computer. Also, many IDE drives refuse to operate on the same
controller card as certain other drives. In particular, Conner IDE
drives are notorious for hating other brands of drives.
Nevertheless, unless you have special needs,
*** JUST SAY NO TO SCSI ***
--
David Arnstein | What do you mean, "get a life"?
arns...@netcom.com | This *is* my life!
Craig Alastair Macbride
>Anyway, here's my little essay, created out of my own bitter experience:
> *** JUST SAY NO TO SCSI ***
Fairer to say:
*** JUST SAY NO TO WINDOZE ***
Everything you speak of is caused by Windoze not providing proper SCSI
support. On every properly written multi-tasking operating system, SCSI
will outperform IDE by a long shot. Once more people start using OS/2,
NT, Linux, SCO Unix, UnixWare, Solaris and (if Microshaft actually get
it right) Chicago, their multitasking performance and ease of adding
peripherals will be severely penalised by using IDE instead of SCSI.
>If you want to use a slow SCSI peripheral such as a CD-Rom drive,
>consider buying a cheap SCSI host adapter just for the CD-Rom, rather
>than buying an expensive h.a. and buying SCSI hard drives.
I am not saying that this isn't correct now, but to suggest that people buy
inferior hardware, just because their current crappy operating system can't
make the most of it, seems like very short-sighted thinking to me.
--
_--_|\ Craig Macbride <cr...@numbat.cs.rmit.edu.au>
/ \ <cr...@yallara.cs.rmit.edu.au>
\_.--.*/ <cr...@rmit.edu.au>
v
John P Sheehy
<cr...@rmit.edu.au> writes:
>arns...@netcom.com (David Arnstein) writes:
>
>>Anyway, here's my little essay, created out of my own bitter experience:
>> *** JUST SAY NO TO SCSI ***
>
>Fairer to say:
> *** JUST SAY NO TO WINDOZE ***
>
>Everything you speak of is caused by Windoze not providing proper SCSI
>support. On every properly written multi-tasking operating system, SCSI
>will outperform IDE by a long shot. Once more people start using OS/2,
>NT, Linux, SCO Unix, UnixWare, Solaris and (if Microshaft actually get
>it right) Chicago, their multitasking performance and ease of adding
>peripherals will be severely penalised by using IDE instead of SCSI.
To all:
What is the highest transfer rate possible with a 340 MB HD and a VLB IDE
controller? I have recently purchased a 486 dx2 66 machine with a VLB
controller, and I only get ~700 KB/S. I have a Commodore Amiga 3000 (16
MHz system) sitting right next to it with a builtin SCSI-1 controller
designed about *four* years ago and I get between 900 KB/s - 1.6 MB/s
with the three HardDisks I have hooked up. Others with the same machine
get upwards of 3 MB/s with >1GB drives. Needless, to say, I am very
dissapointed with the HD speed on the 486. The manufacturer of my 486
motherboard makes a SCSI-2 chip that plugs into the motherboard. If I
get this chip, and install OS/2, what type of transfer rates can I expect?
Would such benefits of OS/2 SCSI support only apply to a native OS/2
environment, or does it help while emulating Windows?
[rest deleted]
Thanks,
John <j...@cup.portal.com>
Darryl Okahata
cr...@yallara.cs.rmit.OZ.AU wrote:
> arns...@netcom.com (David Arnstein) writes:
>
> >Anyway, here's my little essay, created out of my own bitter experience:
> > *** JUST SAY NO TO SCSI ***
>
> Fairer to say:
> *** JUST SAY NO TO WINDOZE ***
It's a bit difficult to do this, as many Windows-based programs are
*SO* nice/easy to use. I think that it's fairer to say:
* Currently, under MSDOS/Windows 3.1, IDE drives will run rings around
SCSI drives. There are many reasons for this: MSDOS is single-tasking
(i.e,., does not need to take full advantage of SCSI features), no
32-bit drivers for SCSI under Windows, etc., etc..
* Under "real operating" systems such as Unix, OS/2, Windows NT, etc.,
SCSI drives will run rings around IDE drives. However, this requires
a good (read: "expensive") SCSI disk controller for best performance;
while cheap SCSI controllers will work, a good controller will give
significantly better performance under a heavy multitasking load.
* I suspect that Chicago/Windows 4.0 will perform best with SCSI drives,
but I do not know this for a fact.
Personally, I'm going with SCSI.
-- Darryl Okahata
Internet: dar...@sr.hp.com
DISCLAIMER: this message is the author's personal opinion and does not
constitute the support, opinion or policy of Hewlett-Packard or of the
little green men that have been following him all day.