4k@60hz gpu

Hi everyone! I've had hackintosh from 2015 and it worked all perfectly...now I've bought a new 4k monitor instead of a normal FHD but when I try to choose the right resolution mac os gives me only two option: 1920x1080 or 1920x2160 which is a really strange resolution. Can someone help me...

4k@60hz: GTX660 has plenty of juice Late in August (after my wife bought a Retina Macbook Pro, actually), I was caught by the 4k bug. Bought myself a 4K monitor (Asus PB287Q), replaced my aging HD5770 with a GTX660, and thought all would be ok. Well, first the good. Works OOB at 60Hz with...