On nvidia list of 4K support, it will run 4K monitors. Also it does support 144hz. It will definitely not run 120 fps any game unless it's a 2003 game at 120fps on a 4K. Even when just working not gaming, the card itself will be working overtime to run a single monitor. It is a low end to medium card and will not perform as well as the other more expensive cards. A 970 or 980 can handle gaming, but really if you are gaming no single GPU, except the Titan X can do 60+ fps ultra on 4K. The Titan X will go like 80fps by itself but ou need SLI to play 120 fps.