hi guys can someone please help with a new gpu instal. the story so far yesterday i took delivery of two gtx 680 and a samsung 840 ssd. i reset the bios and instaled the sdd i then instaled a 680 and the pc wouldnt boot so i tried the other one and the same thing.i put my 6970 back in and the pc booted and i instaled windows on the pc. the chances of two duff card are remote so i must be mising something. ps my motheboard is an asrok series 3 gen 7.