I have a Z77A-GD55 and I can't figure out how to get 4 7970s to work on it. I was able to get 3 working without any problems. Does anyone else have this board?
I am downloading windows 8 right now and will try that, but after reading through this thread, It seems like I shouldn't need to switch from 7 to 8 with only 4 cards.
What graphics driver version are you running? What slots are you using, and are you using powered risers on the x1 slots?
I'm using 1x powered risers for all of the cards. I tried every slot combination I could, and I was using the latest driver. Right now I'm downloading the beta driver and will see if that works.