Bootcamp (WinXP) on MBP | wrong VRAM | 512 MB shared memory, bad performance!

Hi folks,

A couple of days ago while playing Crysis Beta I got the idea to tweak my XP Pro SP2 install for video performance. I noticed that windows thinks my MBP has a 8600mGT with 512MB of RAM. Since we all know it has only 256 the rest must be another 256 assigned as shared memory of the main RAM. Is this bad and will if possibly worsen performance?

No driver I tried, Bootcamp 1.3/1.4 nor Nvidia 163.69/163.71/156.57 change the fact that windows assigns extra RAM to the card.

I'm out of ideas, does anybody know how to fix this or what the problem is? The simulated BIOS probably? Can people please check their own machines' video settings if you have XP Pro SP2 installed.

 

never happened to me -_-; And I don't think it affects performance...

 

do you have the same machine? I have no clue why it recognizes mine with 512MB, never seen extra RAM being applied to a decent card under XP.

I'm not sure about the performance influence though because games might get the idea to take advantage of the full 512MB they see and allocate stuff to all of it. In this case the RAM will be used inefficiently since proper RAM caching is not done anymore. I'm fairly sure it can affect the performance, but not positively.

 

http://forum.notebookreview.com/showthread.php?t=145839

nVidia says that the Turbocache Manager is supposed to "dynamically allocates memory for maximum system performance" so it isn't supposed to decrease performance. The tech brief implies that it works the opposite way you think it does. The Turbocache Manager allocates based on the needs of the application. Haven't seen anything that could allow a user to manually adjust it though.

Edit: Apparently there's an option in Rivatuner you can use to disable Turbocache but it seems you've already seen it.

 

I'm fairly sure it won't affect performance either way. You're being paranoid. If the Crysis beta is unplayable for you and becomes playable after you find a way to disable it, then I'm wrong. I doubt it.

 

I found a way to limit the VRAM available to the game and will see if that does anything. Turning off the turbocache using RivaTuner did not work.

@ Ichigo,
I'm not that paranoid about it but I wonder what if. I don't know how it is implemented. If the game thinks it can use less texture compression since it sees 512 MB it will decrease performance a lot. If the game is aware of this though, it won't make any difference.

 

No it will not "decrease performance a lot" unless you have benchmarks to support that claim. You're playing PC games, not console games. Doom 3 won't set textures to "Ultra" unless you set that yourself.

 

I know what you mean but games put other stuff than just textures in the VRAM. Anyway, of course I don't know about the performance, I'm just wondering. The easiest way to find out would be to deactivate it and test it.... but I can't find a way to do that..