[uglycoyote]

in my experience HDMI works better. I have had Dell 4K monitors both at my home and my work, on three different PCs all have the exact same issue: with DisplayPort I can't get more that 30hz and the mouse is so delayed that it is practically unusable. I almost sent the first monitor back, but when I decided to try the supposedly-inferior HDMI I had no trouble driving it at 60hz and the mouse movement feels buttery smooth (no latency). it's not a case of a weak video card... my card at work easily drives two of these 4K screens at 60 hz over HDMI but for some reason can't drive a single 4K monitor at more than 30 on DisplayPort. what's up with that?