I have been trying for days to get 2 ATI video cards working in crossfire on this mother board. It seems Nvidia has disabled this feature unless you have nvidia GPU's installed. I have read a lot of stuff about this and HP seemed to have accomplished this on a 680i motherboard in a blackbird PC, with a modified bios that let them use SLI and Crossfire. I was wondering if it was possible for someone to do the same for a 790i ultra. When I have both cards installed the system boots fine and both cards work you just can't use Crossfire on the cards.