Optimal resolution and screen size for games?

For 4K small screen)

Marsj
if the bigger the screen, the pixel density for the same 4K will be less

When comparing two screens with just one resolution, but different diagonal, the better the image will be on a diagonal less, because he has pixel density greater.

Igor 24 inch and 3200х1800, 3840x2160 or 4K TRU 4096х2304 in 16:9 aspect ratio.
or
27-inch 5120х 2880 labor for like 5K 16:9, but there is even titan sli rtx did not take out.
in native resolution the value always looks well, especially after tried a double apskeyl. apskeyl above to double on any large format has an opposite effect to the human eye perception.
for monitors of 22 inches with a nominal 1920x1080 16:9 optimum compromise is just 3200х1800.
3840x2160 for 32 inch – the same soap. here you need to have permission in the area 5440х3060 if 16:9, and more, but this is beyond the performance of graphics cards.
PS. who have monitor 4:3, then you 4K equal 4096х3072.

The clarity of a 4K image depends on viewing distance)

Dogma
Have long been the subject chewed. Not to work with a magnifying glass or don't enjoy pixels into a fist, then:
24 DM - 2K
27-30 DM - 2.5 to
30-32 inch 4K