I recently to have a bit more performance on my old Pc change my grafic card from a ATI 9600 Pro 256Mb to a XFX Geforce 6600 GT 128Mb.
With ATI everything runs fine, but with Geforce does not happend the same.
I send some prints to you have an idea because is really hard to describe.
By the way, the problem only happens when playing a game. I play Cabal and Fear and both have the same problem. I have installed the latest Drivers and Direct X, and Remove the older ones. Tryed to roll back the grafic card drivers to the CD version and still does the same.
No that is not the problem, because the GeForce runs the games smother than ATI. And is faster Than ATI. The reason for that is that the ATI ram is DDR2 and the Geforce DDR3.
I've seen that issue before when "FBO" (Frame Buffer Objects" was turned on and the driver/program was buggy. BUT I have also seen it when GPU memory was overheated or going bad. I.e. happens on laptops when gaming. Or when there is insufficient cooling in the computer.
So first thing I'd use the nvidia nTune program to lok at your GPU tem to make sure the entire card is being cooled properly. There was a rrecent version of the nvidia drivers that mesed up the fan and caused overheating.
My Computer
Computer Manufacturer/Model Number
Scratch built
OS
Windows 7 x64 Ultimate
CPU
i7 960
Motherboard
Asus P6X58D
Memory
12 Gig Corsair Dominator
Graphics Card(s)
Nvidia 480
Sound Card
Maudio Delta 44 + breakout box
Monitor(s) Displays
Dell UltraSharp U2410 24in and Samsung 21 dual monitors