I would be getting some Vram testing software to test that GPU, XP should have any issues with 4Gb cards.

Since its a Quadro I doubt it will let you flash the Vbios with a fresh copy but if its an official signed one then perhaps it might, may be worth flashing the card with a fresh copy of the Vbios.

The other thought I have is that it might be the game itself, It may not like 4Gb cards.

I doubt VRAM is the issue here, CMR is an Direct3D 6 game from Win9x era so issues with later GPU's aren't just possible, they are to be expected.

The game has some unofficial patches for Win2k/WinXP/Win7+ that you can find from PCGamingWiki, you could try them out and hope for the best. If they don't help then it's possible only swapping the GPU for older one or playing the game on Win7+ with dgVoodoo 2 will fix it.

Trashbytes wrote on 2024-05-07, 13:47:

I would be getting some Vram testing software to test that GPU, XP should have any issues with 4Gb cards.

Since its a Quadro I doubt it will let you flash the Vbios with a fresh copy but if its an official signed one then perhaps it might, may be worth flashing the card with a fresh copy of the Vbios.

The other thought I have is that it might be the game itself, It may not like 4Gb cards.

Yeah I don't think its the VRAM failing because the card works great with any other games I play as well as bench marking. It scores a 34k in 3dmark05 ran multiple times to make sure. I think its the amount of VRAM. Too much VRAM causing issues with older games. I'm looking for a good deal on an AMD FirePro W4300 that also have 4gb of VRAM to test my theory.

Sombrero wrote on 2024-05-07, 14:15:

I doubt VRAM is the issue here, CMR is an Direct3D 6 game from Win9x era so issues with later GPU's aren't just possible, they are to be expected.

The game has some unofficial patches for Win2k/WinXP/Win7+ that you can find from PCGamingWiki, you could try them out and hope for the best. If they don't help then it's possible only swapping the GPU for older one or playing the game on Win7+ with dgVoodoo 2 will fix it.

I have tested those fan made patches same issues. I know that the game runs on gpu's with 2gb of vram, thats why i wanted to know if its possible to mod the vbios to limit the memory amount. This quadro card will only be uses in windows xp and honestly 4gb of vram is overkill anyway. I'm playing games on my crt with a max resolution of 1280x1024 85hz. Someone on discord already confirmed that the game will run fine on a gtx 750 which is a card that came out around the same time as this quadro and also uses the same drivers from Nvidia. I honestly think its too much VRAM that's causing issues. I have installed need for speed porche unleashed today and the game is working just fine on this card.

lilkuz2005 wrote on 2024-05-07, 22:55:

I have tested those fan made patches same issues. I know that the game runs on gpu's with 2gb of vram, thats why i wanted to know if its possible to mod the vbios to limit the memory amount. This quadro card will only be uses in windows xp and honestly 4gb of vram is overkill anyway. I'm playing games on my crt with a max resolution of 1280x1024 85hz. Someone on discord already confirmed that the game will run fine on a gtx 750 which is a card that came out around the same time as this quadro and also uses the same drivers from Nvidia. I honestly think its too much VRAM that's causing issues. I have installed need for speed porche unleashed today and the game is working just fine on this card.

In my experience having too much VRAM causes the game not to work at all or it won't allow you to select higher graphical settings, things like that, not distorted graphics. While I can't say with 100% certainity VRAM isn't the problem I find it extremely unlikely, instead having too new GPU with too new drivers sounds much more plausible.

Compatiblity with older games, especially with DX6 and earlier started dropping rapidly somewhere along the line with NVIDIA. Also as far as I know CMR only supports 16bit color depth and NVIDIA stopped supporting dithering with GeForce 8 series, so color banding is to be expected even if works with never GPU's. But if the game otherwise works fine with your friends GTX 750 I'd ask him what driver version is he using, check does that driver version support your card and give it a go if it does.

Also Need for Speed: Porsche Unleashed has a bug which forces some textures to the lowest detail if the CPU is too fast, apparently over 2GHz or so. If it doesn't look as good as it should look for unofficial patches for it.

I don't think 32-bit Windows XP can even address 4GB of VRAM?

appiah4 wrote on 2024-05-08, 06:06:

I don't think 32-bit Windows XP can even address 4GB of VRAM?

XP has no issues addressing 4Gb video cards, the only time it has issues is with more than 4Gb of system ram. Perhaps you are thinking of how it maps Vram into system memory, it will only ever map 256Mb of it at a time, this was the issue that Resizable Bar fixed which allows the OS to map all GPU memory at once instead of only a 256Mb block of it at a time. XP cant ever be made to map more than this 256Mb as its a hardware limitation of both the GPU and the Motherboard/BIOS and even if it was available XP doesn't support ReBar. (So no putting XP on a Ryzen and expecting ReBar to work 🙁 )

So XP is fine with 4Gb GPUs, throw in PAE and its fine with more than 4Gb of system memory too.

Yep, before the time of resizable BAR, GPUs stick to the PCI standard of having a max of 256 MB mapped address space available. So Windows XP is technically fine with having more than 256 MB of PCI device memory because the standard doesn't allow for more anyway. However, it is the responsibility of the driver to use the rest of it, usually by somehow changing the address window into device memory. So it could still be some driver quirk or incompatibility in the end, if the card itself is fine.

technokater wrote on 2024-05-08, 07:10:

Yep, before the time of resizable BAR, GPUs stick to the PCI standard of having a max of 256 MB mapped address space available. So Windows XP is technically fine with having more than 256 MB of PCI device memory because the standard doesn't allow for more anyway. However, it is the responsibility of the driver to use the rest of it, usually by somehow changing the address window into device memory. So it could still be some driver quirk or incompatibility in the end, if the card itself is fine.

This is what I am talking about; I do not think nVidia drivers for Windows XP are equipped to handle beyond 32-bit memory address space..

appiah4 wrote on 2024-05-08, 07:43:

technokater wrote on 2024-05-08, 07:10:

Yep, before the time of resizable BAR, GPUs stick to the PCI standard of having a max of 256 MB mapped address space available. So Windows XP is technically fine with having more than 256 MB of PCI device memory because the standard doesn't allow for more anyway. However, it is the responsibility of the driver to use the rest of it, usually by somehow changing the address window into device memory. So it could still be some driver quirk or incompatibility in the end, if the card itself is fine.

This is what I am talking about; I do not think nVidia drivers for Windows XP are equipped to handle beyond 32-bit memory address space..

Its got nothing to do with address space, the Vram is simply not even considered for that as there will only ever be 256Mb of it mapped into system memory, system ram is the only memory limited by that 32bit address space.

As for drivers there also wont be an issue here as they are only ever mapping a single 256Mb block of Vram into system memory at any one time so dont need to be equipped to handle it, this whole issue as mentioned above will be the game itself being written for DX6 when Vram was limited to 512Mb at best.

Still, the driver needs to be aware of the total address space it is managing, even though it has only a single window (that can be actually smaller than 256 MB) to the VRAM. I think that is what the comment is about. Anyway, I think the driver is from around 2015 and 4 GB of VRAM wasn't impossible back then. So I'd assume the driver is aware of this and can handle it.

But back to the issue. It does sound like a compatibility issue with game/driver combo. If newer games work fine, then it is quite likely not a hardware issue. Did you try different driver versions? Comparing with a different card especially if it is from a different chip manufacturer doesn't help much because they don't use the same driver. Even if both cards use different Nvidia GPUs this could lead to different behavior, given game-specific bugs or optimazation in the driver.