Oh well , in that case about only housekeeing on OS that might help is to defrag
PCI-E thing doesn't ad much , a few points in 3dmark

Latest driver isn't always the best , I'd maybe try the 3 latest & bench using 3dnmark or something.
Have you checked your link width in the graphics interface of CPU-Z ??
Select the motherboard tab & look at the bottom section both bocxes should have x16 , there are occasions when it gets screwed and drops to x1
luck
