XP 32 bit Memory
John Callaway
dual boot Laptop with both Windows 7 OS & XP 32 bit OS on it. I would
like to have 8 Gig of ram if it XP 32 will handle it.
JPC
John John - MVP
space requirement for hardware addressing you will not be able to use
the full 4GB, depending on the hardware installed in the machine the
available RAM could be anywheres between 2.75 to 3.5GB.
John
Ken Blake, MVP
wrote:
> How much memory can XP 32 bit OS handle? I want to have Dell build a
> dual boot Laptop with both Windows 7 OS & XP 32 bit OS on it. I would
> like to have 8 Gig of ram if it XP 32 will handle it.
It will not handle it. Neither will Windows 7 (unless it's 64-bit
Windows 7). Moreover, it's very likely considerably more than you can
make effective use of in either operating system.
Here's the scoop:
All 32-bit client versions of Windows (not just Vista/XP/7) have a 4GB
address space (64-bit versions can use much more). That's the
theoretical upper limit beyond which you can not go.
But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.
That's because some of that space is used by hardware and is not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.
Note that the hardware is using the address *space*, not the actual
RAM itself. If you have a greater amount of RAM, the rest of the RAM
goes unused because there is no address space to map it to.
--
Ken Blake, Microsoft MVP (Windows Desktop Experience) since 2003
Please Reply to the Newsgroup
Roy Smith
The most a 32 bit version of Windows can have is 4 GB. That said it is
unlikely that you'll ever see more that 3.2 GB of free memory. This is
because all of your devices attached to your PC take up memory address
spaces for things they need to work (i.e. drivers, etc).
--
Roy Smith
Windows XP Pro SP3
John Callaway
wrote:
OK. I get it. I'll only get 3 gig for ram.
Now what do you think of the idea of a dual boot for XP 32 and windows
7 on the same laptop? Having XP 32 the default OS and using windows 7
when I choose, using a 64 bit processor around 3 gHrtz? I'm wondering
about driver compatibility etc and using XP 32 bit OS with a 64 bit
processor.
JPC
David B.
the laptop mfg's website to see if they provide Windows 7 drivers. There
will be no compatibility issues between x64 hardware and an x86 operating
system, it's been going on for years.
--
--
"John Callaway" <jca...@erols.com> wrote in message
news:0879g5t9uggjss5u5...@4ax.com...
J. P. Gilliver (John)
<rasmi...@gmail.com> writes:
[]
>The most a 32 bit version of Windows can have is 4 GB. That said it is
>unlikely that you'll ever see more that 3.2 GB of free memory. This is
>because all of your devices attached to your PC take up memory address
>spaces for things they need to work (i.e. drivers, etc).
>
>
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf
** http://www.soft255.demon.co.uk/G6JPG-PC/JPGminPC.htm for ludicrously
outdated thoughts on PCs. **
"Bother," said the Borg, "we assimilated a Pooh."
Roy Smith
> In message <#oG0Qc5Z...@TK2MSFTNGP06.phx.gbl>, Roy Smith
> <rasmi...@gmail.com> writes:
> []
>> The most a 32 bit version of Windows can have is 4 GB. That said it is
>> unlikely that you'll ever see more that 3.2 GB of free memory. This is
>> because all of your devices attached to your PC take up memory address
>> spaces for things they need to work (i.e. drivers, etc).
>>
>>
> Is this why many netbooks have a maximum of 2G?
No that's a hardware limitation and has nothing to do with Windows RAM
size limit.
Klaus Jorgensen
> On Tue, 17 Nov 2009 09:03:02 -0600, Roy Smith <rasmi...@gmail.com>
> wrote:
>
>> John Callaway wrote:
>>> How much memory can XP 32 bit OS handle? I want to have Dell build a
>>> dual boot Laptop with both Windows 7 OS & XP 32 bit OS on it. I would
>>> like to have 8 Gig of ram if it XP 32 will handle it.
>>
>>
>> The most a 32 bit version of Windows can have is 4 GB. That said it is
>> unlikely that you'll ever see more that 3.2 GB of free memory. This is
>> because all of your devices attached to your PC take up memory address
>> spaces for things they need to work (i.e. drivers, etc).
>
> OK. I get it. I'll only get 3 gig for ram.
Use the remaining 5Gb as a RAM drive for temporary files etc.
http://www.trap17.com/index.php/4gb-Xp-32bits_t67548.html
--
/klaus
victorhaberkorn
32 bits' OS only suport 3,25 Gig. More than that you have to install a 64 bits.
Ken Blake, MVP
> On 2009-11-17 07:54:18 -0200, John Callaway <jca...@erols.com> said:
>
> > How much memory can XP 32 bit OS handle? I want to have Dell build a
> > dual boot Laptop with both Windows 7 OS & XP 32 bit OS on it. I would
> > like to have 8 Gig of ram if it XP 32 will handle it.
> >
> > JPC
>
> 32 bits' OS only suport 3,25 Gig.
Sorry, that's not correct. The number is variable. Here's the way it
works:
All 32-bit client versions of Windows (not just Vista/XP/7) have a 4GB
address space (64-bit versions can use much more). That's the
theoretical upper limit beyond which you can not go.
But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.
That's because some of that space is used by hardware and is not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.
Note that the hardware is using the address *space*, not the actual
RAM itself. If you have a greater amount of RAM, the rest of the RAM
goes unused because there is no address space to map it to.
> More than that you have to install a 64 bits.
--
J. P. Gilliver (John)
MVP" <kbl...@this.is.an.invalid.domain> writes:
[]
>All 32-bit client versions of Windows (not just Vista/XP/7) have a 4GB
>address space (64-bit versions can use much more). That's the
>theoretical upper limit beyond which you can not go.
>
>But you can't use the entire 4GB of address space. Even though you
>have a 4GB address space, you can only use *around* 3.1GB of RAM.
>That's because some of that space is used by hardware and is not
>available to the operating system and applications. The amount you can
>use varies, depending on what hardware you have installed, but can
>range from as little as 2GB to as much as 3.5GB. It's usually around
>3.1GB.
>
>Note that the hardware is using the address *space*, not the actual
>RAM itself. If you have a greater amount of RAM, the rest of the RAM
>goes unused because there is no address space to map it to.
Since the hardware presumably doesn't need much, presumably the RAM
_beyond_ the hardware address _could_ be used, if someone were to write
a suitable "memory manager" (as used to be done in the early days of DOS
to get round the "640k" limit (and even a little around 1M, IIRR).
Unless the hardware uses incomplete address decoding, that is.
If such a manager were to be written, of course, only software that knew
about it could use it (like DOS software that either knew about being
"loaded high" or didn't), so there probably would be insufficient
usefulness for it to be worth anybody's while, since software houses
would be unlikely to cater for it.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf
** http://www.soft255.demon.co.uk/G6JPG-PC/JPGminPC.htm for ludicrously
outdated thoughts on PCs. **
Odds are, the phrase "It's none of my business" will be followed by "but".
John John - MVP
That won't happen on NT operating systems, the kernel will simply not
allow it.
John
John Callaway
Ken Blake,
I do appreciate all the info on this matter. I recently
purchased a Dell laptop with W7 OS. I could not install some older
programs on it, so I tried to install XP 32 bit OS on a partition
that I resized with W7. The CD/DVD drive would not fully load the
install disc. I returned the computer. I have since done some research
and found out that if I have XP 32 Bit OS on the computer and then
load W 7 on it, it seems to go better. So I intend to buy another Dell
with W 7 OS, then resize the partition, making room for XP 32 bit OS
on the other partition. I will then Ghost the W 7 partition using
Norton. I will then load XP 32 bit OS over the W 7 OS providing the
CD/DVD will read the XP install disc. Then Ghost the W 7 OS on the
other partition. I have downloaded EasyBC boot loader utility to have
the option to dual boot to which OS I want on boot up.
Ken, am I on the right track?
John P. Callaway
Ken Blake, MVP
wrote:
> Ken Blake,
> I do appreciate all the info on this matter. I recently
> purchased a Dell laptop with W7 OS. I could not install some older
> programs on it, so I tried to install XP 32 bit OS on a partition
> that I resized with W7. The CD/DVD drive would not fully load the
> install disc. I returned the computer. I have since done some research
> and found out that if I have XP 32 Bit OS on the computer and then
> load W 7 on it, it seems to go better. So I intend to buy another Dell
> with W 7 OS, then resize the partition, making room for XP 32 bit OS
> on the other partition. I will then Ghost the W 7 partition using
> Norton. I will then load XP 32 bit OS over the W 7 OS providing the
> CD/DVD will read the XP install disc. Then Ghost the W 7 OS on the
> other partition. I have downloaded EasyBC boot loader utility to have
> the option to dual boot to which OS I want on boot up.
> Ken, am I on the right track?
Sorry, although I'd like to help if I could, I've never had any
interest in dual-booting and know next to nothing about it.
Perhaps someone else here can answer your question.
Tim Meddick
multi-booting Windows NT-based OSs (although, personally, I have had some problems
getting the NT bootloader to boot MS-DOS-based Windows...).
==
Cheers, Tim Meddick, Peckham, London. :-)
"John Callaway" <jca...@erols.com> wrote in message
news:jlfnh5pajj95shlpb...@4ax.com...
J. P. Gilliver (John)
>Absolutely no need for "3rd-party boot loaders" as Win7 will easily
>cope with multi-booting Windows NT-based OSs (although, personally, I
>have had some problems getting the NT bootloader to boot MS-DOS-based
>Windows...).
>
>==
>
>Cheers, Tim Meddick, Peckham, London. :-)
>
says won't happen.)
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf
** http://www.soft255.demon.co.uk/G6JPG-PC/JPGminPC.htm for ludicrously
outdated thoughts on PCs. **
Politicians are much like ships: noisiest when lost in a fog.
dennis
> That won't happen on NT operating systems, the kernel will simply not
> allow it.
There is built-in support in the kernel for an application to map
unmanaged memory.
John John - MVP
AWE, only for the applications own use, you can't develop a memory
manager around this, the kernel will not allow this to manage other
processes' memory. On 32-bit systems AWE will only be able to access
RAM above the 4GB barrier if the operating system is PAE capable, 32-bit
XP can't do it. Few applications are AWE capable, this is mostly
reserved for large database programs and other such applications.
John
dennis
I'm not talking about AWE, but about mapping "device" space (physical
memory). That way you can use memory above 4G also in 32bit XP.
XP supports PAE. Its own memory manager just doesn't allow access to
memory above 4G.
John John - MVP
XP supports PAE for DEP only, drivers and applications can't access the
memory above the 4GB barrier. From what I understand memory above the
4GB barrier was available with PAE when XP was released but too many
drivers were misbehaving and causing BSODs so Microsoft decided to put
an end to this in SP1.
I know that a certain RAM disk can apparently make use of the memory
above the 4GB barrier, I guess this is what you mean by "device space".
Although the RAM drive can map the space for use as temporary storage
for other applications the other applications still cannot use this for
their process space, the memory manager does not permit any applications
to directly manage other processes' space. Other than snake oil memory
memory optimizers there are no third party memory managers for NT
operating systems.
John
dennis
> I know that a certain RAM disk can apparently make use of the memory
> above the 4GB barrier, I guess this is what you mean by "device space".
With device space I mean this:
http://msdn.microsoft.com/en-us/library/ms801998.aspx
And yes, some ram-disks uses that to use memory above 4G.
> Although the RAM drive can map the space for use as temporary storage
> for other applications the other applications still cannot use this for
> their process space
True, you need a bit more to use that kind of memory for other than data
storage.
J. P. Gilliver (John)
writes:
When I suggested a memory manager, I wasn't talking about going beyond
the 4G limit, I was talking about accessing the RAM within the 4G but
beyond where hardware sits on some machines, i. e. using non-contiguous
memory.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf
** http://www.soft255.demon.co.uk/G6JPG-PC/JPGminPC.htm for ludicrously
outdated thoughts on PCs. **
Reality and talent shows lack honesty. They manipulate the viewer with mawkish
stories. Contestants turn tragedies into qualifications. - Sean Lock, in Radio
Times, 20-26 June 2009
dennis
> When I suggested a memory manager, I wasn't talking about going beyond
> the 4G limit, I was talking about accessing the RAM within the 4G but
> beyond where hardware sits on some machines, i. e. using non-contiguous
> memory.
That is a hardware problem that you cannot solve with software. That is
why the memory remapping function were invented.
John John - MVP
> John John - MVP wrote:
>
>
>> I know that a certain RAM disk can apparently make use of the memory
>> above the 4GB barrier, I guess this is what you mean by "device space".
>
> With device space I mean this:
> http://msdn.microsoft.com/en-us/library/ms801998.aspx
Thanks for the link. In one of his blogs Mark Russinovich said that
"...problematic client driver ecosystem led to the decision for client
SKUs to ignore physical memory that resides above 4GB, even though they
can theoretically address it." My understanding about this is that
while (some of) the server versions can do this the whole point of
limiting memory access below 4GB on clients with PAE was to specifically
prevent drivers from playing in the upper memory arena. So now I'm not
sure what to think...
http://blogs.technet.com/markrussinovich/archive/2008/07/21/3092070.aspx
Mark's Blog : Pushing the Limits of Windows: Physical Memory
John
J. P. Gilliver (John)
writes:
They seemed to solve it OK in the days of DOS and the (I think it was)
640K barrier, with LOADHI (IIRR) and so on; ISTR prog.s and drivers had
to be loadhigh aware, or something like that. It's all a Long Time Ago
...
dennis
> Thanks for the link. In one of his blogs Mark Russinovich said that
> "...problematic client driver ecosystem led to the decision for client
> SKUs to ignore physical memory that resides above 4GB, even though they
> can theoretically address it." My understanding about this is that
> while (some of) the server versions can do this the whole point of
> limiting memory access below 4GB on clients with PAE was to specifically
> prevent drivers from playing in the upper memory arena. So now I'm not
> sure what to think...
>
> http://blogs.technet.com/markrussinovich/archive/2008/07/21/3092070.aspx
> Mark's Blog : Pushing the Limits of Windows: Physical Memory
You also don't use this function to allocate memory. All the memory
allocation functions that the drivers (normally) use will always
allocate memory below 4G in 32bit XP.
dennis
> They seemed to solve it OK in the days of DOS and the (I think it was)
> 640K barrier, with LOADHI (IIRR) and so on; ISTR prog.s and drivers had
> to be loadhigh aware, or something like that. It's all a Long Time Ago ...
The problem with not all 4GB being usable is because MMIO is overlapping
the address space where your RAM lives. All memory addresses in that
region are redirected to the IO-system. So you cannot get to that RAM.
Memory remapping solves that by remapping ram in that region up above
4G, so you can address it there instead (which 32bit XP doesn't do
willingly).
Chuck
There is another teensy weensy problem.
Microsoft using various means, does not allow legal modification of windows
core by "outsiders" to allow relocation to "unused" memory.
Since hardware, with a proper memory manager, in hardware and software,
usually can do such things, the problem ends up going back to Microsoft's
code.
After all, memory mapping is a very old technique, going back to the
minicomputers, if not farther back in history. Some of the minicomputers
had an rough equivalent to Windows swap file, in that if enough memory was
installed, resided in memory rather than only on disk. At one point, some
of HP's systems swapped out almost anything that was not currently in use.
The ops system maintained a table that was used to find everything.
(1970's) long before Apple, etc. One of the major problems is the
compatibility issue with older P/C hardware and "standards" that are the
result of "IBM compatibility", based on a crippled hardware design intended
to prevent competition with mainframe capabilities and save hardware costs.
The older schemes also were usually intended for use with multiusers, be the
"users" a physical person, or a process.
"dennis" <1...@1.invalid> wrote in message
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