You'll only be able to do 4k@30Hz then. Only HDMI 2.0 and DP 1.2 can support 4k@60Hz, there are no DP 1.2 to HDMI 2.0 working adapters out there that works properly, and there are no DP 1.2 to HDMI 2.0 cables exist. You'd need a lot of computer power to run 4k@60Hz smoothly anyways.