what will happen if i 2k (4k) 144hz display put on this i5 4690k 4.4ghz gtx 1070 ti. how will perform in games. will i lost like 50fps ( fhd 60hz now i play scum high medium settings 90 fps) ?
I'm not 100% sure what you are asking, but if your asking what will happen to your frame rates if you upgrade from a 1080 monitor to a 2k or 4k 144Hz monitor I assure you that you won't be happy. The 1070 is a good 1080 card, but won't be able to put out 144FPS at 2k, let alone 4k on modern games. I suggest upgrading your GPU first, then your monitor. Which card depends on budget, system, PSU, etc.