rig: 3570k@4.3ghz,saphire hd 7950vapor-x(going to buy the same one),GIGABYTE GA-Z77-D3H - Intel Z77 mobo, Seasonic SS-750HT-F3 750W, OEM psu, ? mobo has only 1 pcie 3.0 and 1 2.0, would that be a problem/performance decrease? is psu ok? I googled it and found it has 740w on 12v rail, which is great, but didnt find info if it has the right pins for 2 saphire 7950 vapor-x cards.. please help