Disabling the shared system graphics memory

[succulent95]

My desktop contains a weird motherboard - it's a Gigabyte GA-G31M-ES2L, but it won't let me disable the shared memory. Last year I upgraded the system and added a Nvidia GT520 graphics card with 1gb of its own memory, but it decided to keep 7mb of my available RAM back then (which was 2gb) as shared. I've now upgraded my RAM to 4gb (which is the maximum my motherboard supports, but it's decided to expand the shared memory to just over 1.7gb.
I've tried to disable it in the bios, but I can't because the entry appears to be read only - I think I found somewhere that I had to change it during post?? Anyway, I believe my motherboard's bios is AWARD Bios version f5, and if you want I can post some screenshots.
Any help will be greatly appreciated.
Thanks.

 

[Pandur]

The originally reserved memory is most likely the frame buffer for the integrated graphics. There should be an option in your bios to change the frame buffer size. *edit* I downloaded the manual and you'll find your frame buffer options in the bios under advanced bios features. If the picture in the manual is correct you should look at the three bottom options. Set Init Display First to 'PEG' (your GT520). Onboard VGA to 'Enable If No Ext PEG'. And On-Chip Frame Buffer Size can only be set to 1MB or 8MB (both are so insignificant that I personally would just leave it at 8MB incase you ever remove the GT520 and boots with the igpu) which leads me to believe your problem is a 32-bit OS. */edit*

The extra 1GB that's reserved can be something else entirely, depending on the following:
Are you running a 32-bit or 64-bit operating system?

If you're running a 32-bit OS this is expected behaviour since that can't handle more than 4GB total memory (incl the 1GB on your GT520).


If you're running a 64-bit OS I'll assume your bios just grabbed another GB for it's igpu frame buffer (bios option set to auto maybe?).

 

[succulent95]

[...] which leads me to believe your problem is a 32-bit OS. */edit*

The extra 1GB that's reserved can be something else entirely, depending on the following:
Are you running a 32-bit or 64-bit operating system?

If you're running a 32-bit OS this is expected behaviour since that can't handle more than 4GB total memory (incl the 1GB on your GT520).


If you're running a 64-bit OS I'll assume your bios just grabbed another GB for it's igpu frame buffer (bios option set to auto maybe?).

Well, the machine was brought with a copy of Vista Home Premium 32 bit on it, then a couple of weeks a go I set up a dual boot with Windows 7 Home Premium 32 bit to test it out, and in the last couple of days that's been changed to Windows 7 Ultimate 64 bit.
So, as it stands at the moment it runs Vista Home P. 32 bit and 7 Ult. 64 bit.

 

[MrCaffeineX]

If the memory reservation exists when running both operating system versions, then there is something else going on. If you are seeing a large chunk of "missing" memory when in 32-bit Vista, then it is probably the fact that 32-bit Vista will not address more than 3.25GB or whatever its limit was.

This sounds like the best solution:

The originally reserved memory is most likely the frame buffer for the integrated graphics. There should be an option in your bios to change the frame buffer size. *edit* I downloaded the manual and you'll find your frame buffer options in the bios under advanced bios features. If the picture in the manual is correct you should look at the three bottom options. Set Init Display First to 'PEG' (your GT520). Onboard VGA to 'Enable If No Ext PEG'. And On-Chip Frame Buffer Size can only be set to 1MB or 8MB (both are so insignificant that I personally would just leave it at 8MB incase you ever remove the GT520 and boots with the igpu) which leads me to believe your problem is a 32-bit OS.

 

[bigdogchris]

When you add a GPU with dedicated memory the motherboard automatically disables usage of shared memory for the IGP.

This is a 32 bit OS issue.

 

[succulent95]

I downloaded the manual and you'll find your frame buffer options in the bios under advanced bios features. If the picture in the manual is correct you should look at the three bottom options. Set Init Display First to 'PEG' (your GT520). Onboard VGA to 'Enable If No Ext PEG'. And On-Chip Frame Buffer Size can only be set to 1MB or 8MB (both are so insignificant that I personally would just leave it at 8MB incase you ever remove the GT520 and boots with the igpu) which leads me to believe your problem is a 32-bit OS.

Well I had a very quick look through the manuals before I posted this, but they all related to a different bios version. I couldn't find any documentation or web posts about this motherboard and the f5 bios, which is why I used the term weird originally. I did it anyway just to check, but I have every option except the last avaliable

If it is an OS problem, what would it involve?