Hi I just upgraded from a 7900GT to a BFG GTS 250 1gb. I have 2gb ddr2 800mhz ram, windows 7 32-bit, 500 antec psu, and a biostar mcp6p m2+ mobo. I was playing warcraft III on my 7900gt and my fps were around 60-64 constant, whereas my gts 250 gets 40-60 fps. However, I loaded L4D2 and I received constant 60 fps(highest settings) on GTS 250. The 7900GT would perform only 10-20 fps though. I was thinking it has to do with physx or something... I downloaded the latest nvidia drivers and everything went fine.
i forgot to include i have amd x4 620 quad core @ 2.6ghz cpu