What OS and driver versions are you using? What OS and driver versions are the systems you are comparing yours to using? Do you have all your mobo drivers installed? Is device manager clean, no unknown devices or exclamation points? Most if not all Newer Graphics cards clock down when not under load so its normal to see your clock speeds low.
Main Box*i7 930*GA X58A-UD3R R2*3x4 gig Patriot DDR3 1600EL*EVGA GTX 460 1 gig*Intel X25-M G2 80 gig*WD Green WD20EARS 2 TB*ASUS DRW-24B3LT*Samsung SH-S223L*Corsair AX750 PSU*Rosewill Challenger case*Windows 7 Ultimate 64 bit SP1