2.87GB Usable RAM :(

Buchanan0204 · 4 Apr 2011 at 01:12

Ok. I have 4GB of DDR2 667 ram installed into an Abit IL97-Pro. I am running a x64 bit OS, Windows 7.

On a fresh install, it only detected 3.12GB. I figured this was a limitation of the BIOS or a fault. I checked the manual, it does indeed support 4GB. I then flashed the BIOS to the latest version and it dropped to 2.87GB usable.

It does see the 4GB, so it tells me. Just refuses to use them.

I thought the only thing it could be is my video card stealing some of the system ram, i opened up dxdiag and found it to be nibbling on a whole 1200MB of system ram.

I then thought, I'll install the proper ati drivers, that should sort it. Unfortunately not. Just the same. There isn't an option in the BIOS unlike laptops to limit the amount of ram it uses either.

It's an HD 2400 pro. Surely it doesn't need to steal my system ram, I wont be playing games on it either, so nothing intensive at all.

Is there a way to limit the amount of shared memory on a dedicated card under windows 7 x64?

Cheers.

mikeyholt · 4 Apr 2011 at 09:06

Is onboard graphics enabled in the BIOS?

Hagar · 4 Apr 2011 at 09:44

It may be that if you run something memory intensive, windows 7 will reduce this amount. It is a video caching system I think, when I put 8Gb of memory into my PC I ended up with 3.9Gb free in windows 7 as the video system was allocated a huge amount of memory at start. I have a standalone card HD5750 and onboard graphics is disabled.

andy.

Buchanan0204 · 4 Apr 2011 at 12:50

mikeyholt said:
Is onboard graphics enabled in the BIOS?

There's no onboard graphics. Just a standalone HD2400 Pro.

Buchanan0204 · 4 Apr 2011 at 12:51

nkata said:
It may be that if you run something memory intensive, windows 7 will reduce this amount. It is a video caching system I think, when I put 8Gb of memory into my PC I ended up with 3.9Gb free in windows 7 as the video system was allocated a huge amount of memory at start. I have a standalone card HD5750 and onboard graphics is disabled.

andy.

Pretty annoying isn't it. There must be a way to disable it. Why would Windows think giving 1.2GB of ram to an idle GPU is clever. :confused:

hybrid572 · 4 Apr 2011 at 13:00

I'm pretty sure nkata's right. Windows aggressively caches to memory to speed up applications. That's why loads of people think they need more than 4GB of RAM, as they're already hitting 3.8 or something. In actual fact, that 3.8 is just the maximum their PC can take advantage of.

Hagar · 4 Apr 2011 at 13:03

It's DWM shared memory which is only used if there are a lot of windows open. It is dynamic, so it can be used as system ram and is not locked purely for the graphics card to use.

Buchanan0204 · 4 Apr 2011 at 13:04

hybrid572 said:
I'm pretty sure nkata's right. Windows aggressively caches to memory to speed up applications. That's why loads of people think they need more than 4GB of RAM, as they're already hitting 3.8 or something. In actual fact, that 3.8 is just the maximum their PC can take advantage of.

How is putting my system ram in my idle GPU, speeding up my system?

Kotu · 4 Apr 2011 at 13:06

where are you getting the ram figures from? if you run the resource manager, does it show the full amount with some in use and in standby or is a chunk of it used by hardware reserved?

screenshot of the physical memory chart would be handy.

Buchanan0204 · 4 Apr 2011 at 13:12

Kotu said:
where are you getting the ram figures from? if you run the resource manager, does it show the full amount with some in use and in standby or is a chunk of it used by hardware reserved?

screenshot of the physical memory chart would be handy.

In the resource monitor the said amount is hardware reserved, hence the gpu hogging it for no apparent reason.

Mick-1965 · 4 Apr 2011 at 13:13

The Abit IL97-Pro use a P945 chipset.
The P945 is only a 32 bit chipset, therefore can only address a total of 4GB of ram.

Kotu · 4 Apr 2011 at 13:20

I would take all the memory out and then use memtest to check 1 stick at a time. The graphics card should not be taking variable amounts of system ram and making it hardware reserved.

Buchanan0204 · 4 Apr 2011 at 13:27

Mick-1965 said:
The Abit IL97-Pro use a P945 chipset.
The P945 is only a 32 bit chipset, therefore can only address a total of 4GB of ram.

I took out 1 module to make a total of 3GB. However it was still showing at 2.87GB with the remaining reserved. Why wouldn't it show the full 3GB.

Surely the 4GB isn't including Vram?

Mick-1965 · 4 Apr 2011 at 13:36

Buchanan0204 said:
I took out 1 module to make a total of 3GB. However it was still showing at 2.87GB with the remaining reserved. Why wouldn't it show the full 3GB.

Surely the 4GB isn't including Vram?

The chipset has a 32bit limitation, meaning it can only address a total of 4 GB of ram.
That means video ram, hard drive cache etc and system ram all added together. anything over 4GB is just not used.

Werewolf · 4 Apr 2011 at 13:41

Buchanan0204 said:
I took out 1 module to make a total of 3GB. However it was still showing at 2.87GB with the remaining reserved. Why wouldn't it show the full 3GB.

Surely the 4GB isn't including Vram?

If a system can only address 4gb of memory, it will include everything with a memory address.
Your Videocard has memory so that's included, even things like your soundcard and the USB controllers will have some memory that needs addressing so that will be used.

IIRC the way it works is that the system addresses memory in the order of
IO memory - memory addresses used for the motherboard/basic IO features (things like hard drive controllers, the keyboard etc).
Video Memory - the memory addresses related to the the videocard
System memory - the ram you've got in your system.

Kotu · 4 Apr 2011 at 13:48

im guessing its a 256MB video card? the totals would be right then with the 1 module removed. Maybe the one you removed is damaged?

Hagar · 4 Apr 2011 at 13:54

Buchanan0204 said:
How is putting my system ram in my idle GPU, speeding up my system?

It is a dynamic allocation of system ram in case it is required. It is the way windows 7 and vista work. there is no way to reduce it. It does not slow down the applications that need system ram, it allows the operating system to use this allocation for its graphic purposes and potentially speeding up the computer.

This is nothing to do with 4Gb limits as later posters have said. Read the first post you know it makes sense.

andy.