I am currently using a MacBook Pro 13" 2015 model with a Samsung U28D590 UHD display.
Currently I am using the HDMI port of the monitor with a mini-displayport to HDMI adapter and receive 4K 30hz output. The display is kind of laggy at the moment, with noticeable input lag with the mouse being the main issue.
When I switch to a lower resolution it returns to 60hz output and it is much smoother (less pixels) and the mouse input lag is gone.
My question is if I just use a displayport cable and receive 4K 60hz output, will this input lag disappear?