Are you playing on default maps? Have you enabled multi-threaded rendering? Have you turned down Anti-aliasing?
Yes, yes, no. I guess there's not really any notable difference between x4 and x8 in the heat of the action, so that's probably an easy way to improve performance.
Couple things. If your using Fraps to check your fps then turn it off before you play . Fraps has a tenancy to bring down your FPS in some games. To check it in game open the console and type in net_graph 1.
Naw, still choppy with FRAPS off.
Next test with mult-core rendering on, and then off. It doesn't always improve FPS on some rigs (like my own E8400)
It's always been on, I'll try it off. But I do have a quad-core, so I would imagine... whatever, I'll give it a shot.
EDIT: Turning off multi-core rendering helped considerably. Now it averages around 45FPS and only gets choppy in the very busiest moments. Turning off motion blur and bloom should do the trick and give me very playable framerates. Thanks!