There are tomes on the web about 30 or 60Hz from video cards. Here's a taste.
I could be wrong but those cards need to be connected with displayport to get to 60. If the 4K TV has such.
I have a Samsung hu8550 and a R9 295x2 and the max resolution I see is in desktop is only 1920x1080 is there a way to get 3840 x 2160 like your suppose to?