I am having some problems with my 4 gigabyte OC 7970s. As I said a few months ago, I somehow got all of them to run at 730kh/s at 1040/1500 with the BIOS that came with it. Last month, one of them had a capacitor that exploded on the back of the board, so I RMAd it and got a new one yesterday. I put it in my rig and set it up like it was before my 4th card died, and now I can only get 550kh/s. I didn't change any settings going from 4 to 3 cards, so I am thinking the newer card is causing it somehow. Could it be the newer card, or what?