Nvidia card (6800) on an ATI motherboard?

[hamburglar]

I have a Shuttle ST61G4 which has the ATI 9100 IGP - RS300 / IXP150 chipset.
More information here: http://www.hardocp.com/article.html?art=NTYy

I disabled the onboard video and added a BFG 6800OC, but I am getting low performances (~2200 on 3dMark05). I've read that most people get around 3500-4000 on 3dMark05. Could the hit in performance be due to my motherboard? If so, would an ATI video card do better? Thanks for any input or help.

System specs:
Northwood 3.2GHz @ 3.4 GHz
2x512 PC3200 Kingston Value Ram
74GB Raptor HD

 

[RussianSensation]

install the latest chipset drivers
install latest nvidia drivers (try 75.xx)
make sure everything is set to performance and anti-aliasing and anisotropic filtering are disabled in the nvidia control panel. Install DirectX9.0C from microsoft.com

ATI onboard drivers should be uninstalled just in case. Use driver cleaner to clean them before new nvidia driver install.