y motherboard is a p8z77-v Premium. May be heat...the two 7950 cards were running, and while they were, I touched the heatsink on the side of the 7970, and it was hot to the touch...and it not even running. Maybe heating issues? Maybe something else. The motherboard temperature is 44C (note: I only have two cards in the system now, since this way I get 975 KH/s, compared to only 750 KH/s...I'm mining feathercoins ATM).

Pvtbrutus: What is the amperage of the current PSU I'm using? I can't find it anywhere on Newegg's site, but I do know this PSU was recommended by JohnnyGuru.