What everyone seems to be missing here is the core of almost all fps issues when gaming with a semi decent rig. Please note, every pc is as good as its weakest component. If you have a decent GPU, PSU, CPU, RAM, MB, etc, then 9 times out of 10 it's your HDD... Unless your HDD is a SSD or 10000rpm WD raptor (which will nly give you 33% more than most) its your shitty 7200 HDD causing all your issues. Think of it as a connected system, where the weakest component bottle necks the rest.
Also your overriding graphics config (sli, xfire, CCC settings etc) can affect your gpu. Although if your gpu, CPU etc can cache, R/W etc though ram to the HDD faster than the HDD can respond and act, again that's your HDD's problem..... unless you have no idea about the associated drivers and software.
Also ensure when you update your gfx driver you do a clean sweep. Especially with ati. Oh, don't forget the files they store in the registry too.
One more thing.., sorry. The components temperature dramatically affects performance. Especially gpu. So make sure it's not over heating more than speced on full load. With put liquid cooling it's all about air flow... Cool pushing though the front and fans pulling the hot through the back. pc gaming 101.
BR
Electronic engineer