maybe at 1024x768-1280x1024 IE bench resolutions
Gaming at 19**x**** I doubt raising the cpu speed from 3.8ghz (techpowerup article) to 4.2ghz would net you much gain at all.

Check the OC results, 750 1000 to 950 1300 increased frames %20 in some cases. That wouldnt happen if the card was being choked by the cpu.