I have a x370 Asrock killer sli/ac MB both x16 slots recognize both cards independently. I thought about plugging in a second monitor last night after OP and when I did the 480's fan started blowing full blast and both screens went black. Now the 580 won't show up even solo it displays but doesn't get recognized by any software like adrenalin, trixx, claymore, ETC. By that point I had to go to bed since I had 3hr left before I had to go work. As far as getting a mining board I can't invest in all that yet it's more than just buying a MB need cpu ram etc. Really need to get this going first till I can afford an upgrade.

 How do I check crossfire status?

Someone mentioned checking the UEFI what settings am I looking for?

I guess I'll order a riser and see what happens I can afford $7 for now.