Reduce Vista Video memory allocation

Dear All,

I have 4GB of RAM, and a nVidia 8600M with 256MB of RAM.

However, the system allocated 800MB for the video, leaving only 3.2GB
for the system.

May I know how can I reduce the shared memory?

Thanks in advance.

CKKwan <> wrote in news:3f3ff0ab-f1d8-4286-bd19-
:

> Dear All,
>
> I have 4GB of RAM, and a nVidia 8600M with 256MB of RAM.
>
> However, the system allocated 800MB for the video, leaving only 3.2GB
> for the system.
>
> May I know how can I reduce the shared memory?
>
> Thanks in advance.
>

No it didn't. You are using Vista32bit and need to switch to Vista64bit to
get use of all of the ram. 32bit OS can only utilize a max of 4GB of memory
address space and all of your hardware needs address space too so that is
subtracted from the 4GB of usable ram. Use a 64bit OS and you won't have
that limitation of 4GB total address space.

"CKKwan" <> wrote in message
news:3f3ff0ab-f1d8-4286-bd19-...
> Dear All,
>
> I have 4GB of RAM, and a nVidia 8600M with 256MB of RAM.
>
> However, the system allocated 800MB for the video, leaving only 3.2GB
> for the system.
>
> May I know how can I reduce the shared memory?


Are you running Vista 32-bit?

ss.

"CKKwan" wrote:

> However, the system allocated 800MB for the video
> May I know how can I reduce the shared memory?

"shared" means the memory can be used by both OS's applications and graphics:
if you're not playing games it will be used by normal applications.
if you're playing games it will be used by graphics card/games.
Don't care about it.

CKKwan <> wrote:

>Dear All,
>
>I have 4GB of RAM, and a nVidia 8600M with 256MB of RAM.
>
>However, the system allocated 800MB for the video, leaving only 3.2GB
>for the system.

I think you're misinterpreting what you're seeing. You need 256MB of
address space for your video RAM, and a bunch more address space for
your BIOS, and maybe some more for other things. That's why you're
down to 3.2GB.

The only way around that is to expand the available address space. And
the only way to do that is to go to a 64-bit OS.

--
Tim Slattery
MS MVP(Shell/User)

http://members.cox.net/slatteryt

On Wed, 13 Aug 2008 06:05:41 -0700 (PDT), CKKwan <>
wrote:

> I have 4GB of RAM, and a nVidia 8600M with 256MB of RAM.
>
> However, the system allocated 800MB for the video, leaving only 3.2GB
> for the system.


No it didn't. Here's the situation:

All 32-bit client versions of Windows (not just Vista/XP) have a 4GB
address space. 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. The rest of the RAM goes unused because there is no
address space to map it too.



> May I know how can I reduce the shared memory?


There's nothing to reduce. The only way to use more memory is to use
64-bit Vista.

Why do you need so much memory? Unless you use particularly
memory-hungry programs, it's unlikely that you would see any
performance improvement by going above 3.2GB.

--
Ken Blake, Microsoft MVP - Windows Desktop Experience
Please Reply to the Newsgroup

> No it didn't. Here's the situation:
>
> All 32-bit client versions of Windows (not just Vista/XP) have a 4GB
> address space. 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. The rest of the RAM goes unused because there is no
> address space to map it too.

Yes, I am using 32bits OS, and aware about the 4GB limitation. 64Bits
applications are not as available as 32bits yet, and this is the fact
I can't change now.

However, I do not understands why the Hardware used up 800MB, isn't
that just too much?

x86 is having a different address spaces for I/O and RAM. Only the
Video needs to share the RAM address space because of performance
issue (HDD and etc uses DMA which doesn't consume RAM as Video). I am
just wondering if it si not the Video driver then who else is using up
the RAM?

I need more RAM because I am doing some testing recently and need to
fireup at least 3 Virtual PC together, toether with VS2008 and a bunch
of other memory hungry softwares

<> wrote in message
news:d8ef9d4c-cdbc-4e00-a988-...
>> No it didn't. Here's the situation:
>>
>> All 32-bit client versions of Windows (not just Vista/XP) have a 4GB
>> address space. 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. The rest of the RAM goes unused because there is no
>> address space to map it too.
>
> Yes, I am using 32bits OS, and aware about the 4GB limitation. 64Bits
> applications are not as available as 32bits yet, and this is the fact
> I can't change now.

Well, you do not seem to be aware that you can run almost all 32-bit
software on Vista 64-bit. It's drivers that are the issue more than
anything else, and with a laptop, it is a simple black or white answer
whether you can run it or not.

> However, I do not understands why the Hardware used up 800MB, isn't
> that just too much?
>
> x86 is having a different address spaces for I/O and RAM. Only the
> Video needs to share the RAM address space because of performance
> issue (HDD and etc uses DMA which doesn't consume RAM as Video). I am
> just wondering if it si not the Video driver then who else is using up
> the RAM?

Didn't you read what he said? Nothing is using it. It's just unavailable.

> I need more RAM because I am doing some testing recently and need to
> fireup at least 3 Virtual PC together, toether with VS2008 and a bunch
> of other memory hungry softwares

Whinging about it is not going to change the facts.

ss.

<> wrote in message
news:d8ef9d4c-cdbc-4e00-a988-...
>> No it didn't. Here's the situation:
>>
>> All 32-bit client versions of Windows (not just Vista/XP) have a 4GB
>> address space. 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. The rest of the RAM goes unused because there is no
>> address space to map it too.
>
> Yes, I am using 32bits OS, and aware about the 4GB limitation. 64Bits
> applications are not as available as 32bits yet, and this is the fact
> I can't change now.
>
> However, I do not understands why the Hardware used up 800MB, isn't
> that just too much?
>
> x86 is having a different address spaces for I/O and RAM. Only the
> Video needs to share the RAM address space because of performance
> issue (HDD and etc uses DMA which doesn't consume RAM as Video). I am
> just wondering if it si not the Video driver then who else is using up
> the RAM?
>
> I need more RAM because I am doing some testing recently and need to
> fireup at least 3 Virtual PC together, toether with VS2008 and a bunch
> of other memory hungry softwares

Nothing else is using the RAM, it just is not available because Windows
can't find/see it.
It's like trying to navigate around in Canada with a US map database loaded
in your GPS.
No matter how much you look, you won't find where you are. It's off the
available map.
A 32 bit OS can only use 4GB memory, in total, because of the way the
software is written.
Any more than that is 'off the map'.
If you absolutely have to have more RAM, you MUST use a 64 bit OS.
If you have 4GB and allocate enough virtual memory, the machine should still
do what you want, just not quite as fast as you may want.

wrote:

>However, I do not understands why the Hardware used up 800MB, isn't
>that just too much?

No, not at all. A few folks with really fancy video cards, especially
if they have more than one, burn more address space than that.

>x86 is having a different address spaces for I/O and RAM.

No, it doesn't. It has a fixed amount of address space. In a 32-bit
OS that's 2**32 = 4GB. That address space has to be used to access
*everything*.

> Only the
>Video needs to share the RAM address space because of performance
>issue

I think you're confusing shared RAM and the address space issue. Some
computers are configured so that the video adapter uses system RAM
instead of having its own. But whether it's sharing system RAM or
using its own memory, some of that 4GB address space must be used to
access whatever memory it's using.

>I need more RAM because I am doing some testing recently and need to
>fireup at least 3 Virtual PC together, toether with VS2008 and a bunch
>of other memory hungry softwares

Three VPCs + Visual Studio sounds like a pretty RAM-hungry mix. You
might benefit by moving to a 64-bit platform. Even if you're running
32-bit apps, you'd benefit from the additional RAM (less swapfile use
would be needed).

--
Tim Slattery
MS MVP(Shell/User)

http://members.cox.net/slatteryt