*CPU is not that bad...dont be such a dick swifty
@the Op, it could be system memory (probably could use more than 4GB regardless)...or a driver issue. I'd try re/installing latest nVidia drivers and see how you fare.
You can also monitor system resources while youre gaming and see whats out of whack...CPUID, EVGA Precision X are good tools to check things out. Good luck friend, let us know if you find anything