I have my resolution on highest and game settings on all high and I got a smooth 330 fps thats just cuz I got a $400 video card.
You got get graphic card optimizers for better performace but I'd recommend purchasing a new video card.
frys.com and circuit city.com are having a special 809mb gtx275 for only $150 it use to be $250 or w/e...
gtx285 2gb ftw edition is da best!