It should be able to, yes. With slight OCing, the 4670k will draw about 100W. Each 780 draws 250W. That, in total, is 600W. Those components are generally what the largest amount of the power draw consists of. An AX760 would work, but if you wanted to moderate-high OCs on the cards as well as the processor (which I would recommend), then you should get the AX860 in order to play it safe. It all depends on how much OCing you want to do.