I thought the macbook with amd was fine on 4k especially after getting the right cable for 60hz. The i5 with intel 530 is better. Maybe it is because graphics cards are designed more for 3d processing than for general 4k performance. I tried playing a 2d shooting game on each and for whatever reason the intel 530 system was less latent and much easier to win. The macbook is as smooth as the intel 530 when on its native screen but not when it drives a 4k screen.