XP SP3.
If I have 4GB RAM XP can only access ~2.6GB RAM, because there are RAM
memory mapped to by drivers like video card, ...etc?

What if I have a 1 GB memory video card? Is that mean my accessable RAM will
be lesser than 2.6 GB?

How the memory amount of video card affect the accessable RAM?

Alan T wrote:
> XP SP3.
> If I have 4GB RAM XP can only access ~2.6GB RAM, because there are RAM
> memory mapped to by drivers like video card, ...etc?

It's closer to 3.1 or 3.2 GB. A 32-bit OS can only use 4 GB of RAM
theoretically, but in practice your hardware is using RAM, too.

> What if I have a 1 GB memory video card? Is that mean my accessable
> RAM will be lesser than 2.6 GB?

Actually, if you have an *onboard* video card, Windows will wind up with
less memory. A standalone video card, however, uses its own memory, so
it will not take away any from what would otherwise be used by Windows.

"Alan T" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> XP SP3.
> If I have 4GB RAM XP can only access ~2.6GB RAM, because there are RAM
> memory mapped to by drivers like video card, ...etc?

With 4 gig, properly configured, the maximum avalable is around 3.2 gig.

> What if I have a 1 GB memory video card? Is that mean my accessable RAM
> will be lesser than 2.6 GB?

No, in that case, you have more of the RAM available to you.

> How the memory amount of video card affect the accessable RAM?

If the memory is onboard to the video card, it doesn't affect the system RAM
at all.

It's on systems with embedded video chips that *share the system RAM* where
you will see a reduction in available RAM, based on the amount of memory the
video chip claims from the system RAM.

HTH
-pk

Alan T wrote:

> How the memory amount of video card affect the accessable RAM?

It depends. Usually, it will reduce the total address space (which is
4GB) by 256MB per GPU plus some small amount.

dennis <(E-Mail Removed)> wrote:

>Alan T wrote:
>
>> How the memory amount of video card affect the accessable RAM?
>
>It depends. Usually, it will reduce the total address space (which is
>4GB) by 256MB per GPU plus some small amount.

Bullshit. If the video card has dedicated memory, there will be no
hit. If it uses "shared memory", that amount will be the hit.

"If the video card has dedicated memory, there will be no hit".

I don't think that true. Yes, a video card with dedicated memory will use this dedicated memory
rather than share part of the motherboard RAM, but, there will still be a hole in the motherboard
RAM address space that simply won't be used since the video card RAM still uses up part of the
4GByte address space. The larger the amount the video card internal RAM, the less motherboard RAM is
available. 32-bit versions of Windows don't use it since some drivers might crash the OS if it did
use it.



"Mike Torello" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
dennis <(E-Mail Removed)> wrote:

>Alan T wrote:
>
>> How the memory amount of video card affect the accessable RAM?
>
>It depends. Usually, it will reduce the total address space (which is
>4GB) by 256MB per GPU plus some small amount.

Bullshit. If the video card has dedicated memory, there will be no
hit. If it uses "shared memory", that amount will be the hit.

Mike Torello wrote:
> dennis <(E-Mail Removed)> wrote:
>
>> Alan T wrote:
>>
>>> How the memory amount of video card affect the accessable RAM?
>> It depends. Usually, it will reduce the total address space (which is
>> 4GB) by 256MB per GPU plus some small amount.
>
> Bullshit. If the video card has dedicated memory, there will be no
> hit...

That is not true. The video card (and other PCI devices) will reserve
exclusive address space at the processor and in turn this reserved
address space will not be available to the RAM, the RAM in effect will
go unused because it has no address space available at the processor.
The only way around that problem is to map the memory without addresses
above the 4GB arena and use PAE. (DEP aside) PAE is not available on
Windows 32-bit client versions, this feature is only available on some
of the Server versions. The only way around this for client operating
systems is to move to the 64-bit platform.

John

Mike Torello wrote:
> dennis <(E-Mail Removed)> wrote:
>
>> Alan T wrote:
>>
>>> How the memory amount of video card affect the accessable RAM?
>> It depends. Usually, it will reduce the total address space (which is
>> 4GB) by 256MB per GPU plus some small amount.
>
> Bullshit. If the video card has dedicated memory, there will be no
> hit. If it uses "shared memory", that amount will be the hit.

It is based on available address space. All devices have to fit in the
address space. The amount of RAM that can be accessed, is whatever is
left after peripherals such as video cards (with their own private memory)
have been provided for. If you have 4GB memory and a 1GB video card,
the total address space required is 5GB. A 32 bit Windows which can only
support a 4GB address space, can't handle it all. What happens is, the
1GB video card private memory is fully addressible, plus 3GB of the system
memory can be seen. 1GB of memory is lost to the OS and cannot be used.

The 256MB quantity Dennis is referring to, is the smallest block
size allocated by the BIOS. The BIOS does initial address space
planning for the system. If there is a PCI bus, 256MB may be
allocated to it, even if only one byte of storage is sitting
there on the PCI bus (like the registers on some PCI chip).

The PCI Express bus works in a similar way, with a round up to
the next largest 256MB sized quantity. So the atatement in the first
paragraph, about 1+3, is not quite correct. The usable memory might
end up being slightly less than 3GB. And that is what makes the
~2.6GB number mentioned, quite believable.

Paul

Paul wrote:
> Mike Torello wrote:
>> dennis <(E-Mail Removed)> wrote:
>>
>>> Alan T wrote:
>>>
>>>> How the memory amount of video card affect the accessable RAM?
>>> It depends. Usually, it will reduce the total address space (which is
>>> 4GB) by 256MB per GPU plus some small amount.
>>
>> Bullshit. If the video card has dedicated memory, there will be no
>> hit. If it uses "shared memory", that amount will be the hit.
>
> It is based on available address space. All devices have to fit in the
> address space. The amount of RAM that can be accessed, is whatever is
> left after peripherals such as video cards (with their own private memory)
> have been provided for. If you have 4GB memory and a 1GB video card,
> the total address space required is 5GB. A 32 bit Windows which can only
> support a 4GB address space, can't handle it all. What happens is, the
> 1GB video card private memory is fully addressible, plus 3GB of the system
> memory can be seen. 1GB of memory is lost to the OS and cannot be used.
>
> The 256MB quantity Dennis is referring to, is the smallest block
> size allocated by the BIOS. The BIOS does initial address space
> planning for the system. If there is a PCI bus, 256MB may be
> allocated to it, even if only one byte of storage is sitting
> there on the PCI bus (like the registers on some PCI chip).
>
> The PCI Express bus works in a similar way, with a round up to
> the next largest 256MB sized quantity. So the atatement in the first
> paragraph, about 1+3, is not quite correct. The usable memory might
> end up being slightly less than 3GB. And that is what makes the
> ~2.6GB number mentioned, quite believable.
>
> Paul

Page 8 here, has an example address space allocation. I wish Intel
would release a new version of this document, because there are
many useful examples they could include, which are not covered
here in detail. This document is a little too old, to be really
useful (needs newer chipset examples).

http://dlsvr01.asus.com/pub/ASUS/mb/4GB_Rev1.pdf

Paul

Did you eat an extra bowl of stupid lately?
"Mike Torello" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> dennis <(E-Mail Removed)> wrote:
>
>>Alan T wrote:
>>
>>> How the memory amount of video card affect the accessable RAM?
>>
>>It depends. Usually, it will reduce the total address space (which is
>>4GB) by 256MB per GPU plus some small amount.
>
> Bullshit. If the video card has dedicated memory, there will be no
> hit. If it uses "shared memory", that amount will be the hit.