Video Lag in COD4

[The_Humungus]

I have a Nvidia 7950GT card, and a Vista dual core box. My drivers are up to date. On some of the maps, Downpour especially, frequently my fps drops below 20 and the lag causes me to get my butt shot off. I know its a graphic intensive map, but I have the Optimal System Settings selected, and still get very low FPS on some of the maps. On some of the maps, the FPS does not drop below 90.

Is there anything that can be turned on or off to as far as graphic selections in the game to improve this? Or is it just the fact my video card can't handle some of the maps?

Thanks.

[InfinityDevils]

Make sure you have Anti-Aliasing OFF as well as Sync Every Frame OFF.

There are a few others but those can be useful in battle, such as Shadows.