I have a 7800GS in a system running Vista business(2nd box in my sig) and when I try to play "Day of Defeat:Source" the performance seems very low.

I often only get average 29-32fps(21fps lowest) in this game. This is with 1280*1024 and every graphics setting turned down to the lowest. I'm using the latest vista 32bit driver 158.24. On my XP box using 7950GT I can get average 60fps(53fps lowest) in this game with 1600*1200 and everything turned to max. I understand that 7950GT is better hardware but I didn't realize the difference could be this big.

Am I doing something wrong or is this the performance to expect for 7800GS in vista?