I just bought Sapphire 4870 and on my system it scores 10700 on 3dmark06. My previous card ( 3870) scored 9500. This as much as i know is very low score for the 4870. Any ideas why might that be? My processor is amd 5600+ and the psu is CoolerMaster real power 520w,( which is sufficient, if the psu is not broken in some way). Is it possible that i have a faulty card?