I recently formatted my system, and installed all of the latest drivers. I run an AMD X2 3800+ , 2 gigs DDR400 Ram, an 8800GTS 320mb and Windows XP. I get absolutely horrible framerates, in the crysis beta I never get over 20 fps while running medium settings on 1024x768. As well as in Bioshock, Counter Strike Source, and Medal of honor Airborne I am getting low FPS.
I got to thinking, I only have a 400w PSU, could this be the issue? Could a PSU be the cause of low performance for a system that is decently mid - high end?