Hi guys .
I bought a 9800GT 4 days ago , it worked great in the first 2 days .
In the 3rd , I noticed some weird texture flickering in Assassin's Creed , I thought it was a bug in the game , but when it happened in burnout Paradise too !
So I installed FarCry 2 to see what's gonna happen , and SURPRISE ! It was even worse than the Assassin's Creed , textures flickering and shaking , specially terrain and water textures , it's ugly .
left 4 Dead looks like crap , almost (if not all) every game I have suffers from this problem .
Don't ask me about the driver version , because I tried all of them .
It sounds like a heat issue. I have two MSI 9800 GTs in SLI but I stress tested both for benchmarks individually in different motherboards (Furmark, 3DMark06). They will start to put out artifacts near 75-80 Celsius.
Try running GPU-Z or realtemp in the background while you game. They both will write to a log file every 5 or 10 seconds that you can review to check hogh temps and if they happen when you see flickers, artifacts. All videocards will put put strange textures (or crash) as they near their temperature limits.
One other thing to try is to intall Nvidia's Ntune utility and then manually set your fan to 100 percent prior to gamimg. If that fixes the problem, then you have a heat issue and you need better airflow or a case fan to blow right into the side of your 9800 GT.
It sounds to me like your GPU is either not getting enough power or has unstable memory.
Please post your full system specs including any overclocks, your PSUs manufacturer, wattage and +12v amperage.
Try using Rivatuner to underclock your GPUs memory and see if you still have the artifacting problem.
Assuming your card started at stock clocks (ie, you have not overclocked it) and underclocking the memory fixes the issue, you should make an RMA request as you have a faulty card.