I’m searching for a display 4k or 2k but there is a difference in the refresh rate the 4K only has a 60hz while the 2k has 120hz, I use it for gaming and everyday tasks and some designing so should I go with the more resolution or with the higher refresh rate?
High refresh rate is wonderful. You can’t go back once you try it. I personally use a 144hz 1080p panel as my main display, with a side 60hz 1080p panel for content watching. Gaming on 144hz or just 60+ hz is wonderful, can’t recommend it enough. If your designing a lot, then the 4k panel can’t be rulled out. Personally, hz > resolution for gaming. But increasing resolution is kick ass for productivity.
What is your graphics card?
4K more eye candy, 2K better performance. And size matters. What sizes are you looking at?
I’m going to upgrade soon and I’m leaning towards 4k with IPS color reproduction over hz because I don’t play games like CS:GO, so 144hz wouldn’t have much of a point.
Personally I take framerate over graphics anyday, its a much better experience to have smooth motion than nice grahics (imo), I always lower my settings so iI hit 75hz, and just yurn up the AA until it doesnt hit that, I always get fps and AA above everything, all the eye candy is second.
And now a wild ultrawide user appears. What about something in the middle 95 Hz IPS 1440p in 21:9?
Having both types of monitors, I would recommend the 4k @60Hz over the 2k @120Hz, unless you play CS-GO or any other competitive FPS that requires a quick refresh rate. If your like me and you play MMOs or other non-fast pace games, you’ll appreciate the pixel density over the refresh rate much more (specialy if your upgrading from a 1080p monitor).
If you want the uber BEST 
…go with a 4K OLED screen…amazing colors, amazing blacks…it’s pixel heaven !!!
The only thing that beats that currently is the DELL 8K screen 
…but you won’t be able to game correctly on that screen. 4K is really playable …I play 4K with a GTX 1080 with all details Ultra and I get a very acceptable fps (40-60 fps).
