try taking one of you GPU out and test both slots with 1 card and then you know if it the mobo or just looks like it could be a driver problem :/
P.s just asked a friend and its Overclock issue on the GPU's
Ive overclocked mine since day 1 and always asked 110%
Mine are probably just dead x)
Gtx1080 here i comeeee (when i have some moneyz)