After replacing the cards, removing all the drivers I could find (Driver Sweeper just caused windows to BSOD - joy!) and installing the new drivers, I found that I had no performance improvement whatsoever! In fact, my performance if anything got worse!
I tested this both in Bad Company 2 using fraps and World in Conflict's benchmark. With my old card I was averaging 30 fps in BC2, now I'm getting 15-25. I don't have old data for WiC, but I was averaging 28 with the new card.
I tried updating with the latest drivers, things got worse. WiC's average dropped to 24.
I'm currently running two monitors, my primary at 1600x900 and my secondary at 1280x1024. CPU is a Core 2 duo 6420, 4.00 GB of RAM. OS is Windows 7 x64.
Does anyone have any suggestions on how I can improve this performance? Going from a three year old card there should have been a significant improvement. The only thing I haven't tried yet is reinstalling Windows.
Hmmm. I would definitely hold off on reinstalling windows. It sounds like there may be some configuration required. Also, have you seen the new ati 10.4 preview drivers? They had some BC2 specific fixes.
Running the two monitors could be a concern, are they in extended desktop mode or clone? Also are you using ATI's catalyst? Make sure you aren't forcing AA of Anisotropic filters through catalyst.
Sounds like you know what you are doing, those are things I can think to check off the top of my head.. OH, and this may be a long shot, but if your mobo has half decent integrated graphics with that setup it MAY be possible that the intergrated graphics are active, not the ati card. Anyway, best of luck!