One of the biggest reasons why gamers are avoiding 4K monitors is that there’s no affordable graphics setup one can buy to play the latest and greatest at the resolution at playable frame rates. (opinions vary on what that means, but my take on it is at least 30FPS)
So you’re left with a compromise if you want to play at 4K: either you can tone the settings down, or you can tone the resolution down. But is it really that bad to tone the resolution down if one is adamant about keeping the settings and effects at maximum?
Let’s take a look at Sniper Elite 3. I just chose this at random. Plus it’s one of the few games with a fully rendered main menu that so I don’t have to worry about consistency. The monitor I used is Dell’s P2715Q, a 27” 4K monitor.
Here’s what it looks like at 4K
Here’s what it looks like at 2560x1440
And just for fun, here’s what it looks like at 720p
While there are noticeable differences in the 4K and 2560x1440 image (notably the rifle’s buttstock and the letters A and N), keep in mind that the camera is equivalent to being about two inches away from the monitor.
Speaking of which, the monitor’s pixel density is 162PPI. While this is a far cry from the 400 PPI of 1080p smart phones, you’re also not looking at it at the same distance. Give or take you’re looking at a phone about three times closer than a typical monitor, at least for me (I hold my phone about 4-6 inches from my eyes, the monitor is about 18 inches away)
I don’t know the maths about effective PPI and distance, but if we were to assume a linear relationship, I’m getting a “Retina”-look.
So is it bad to play at a lower, non-native resolution? I’d say it depends on your monitor. If your monitor is specced to work well with 100% scaling on Windows, I’d say don’t do it if you can avoid it. You’ll certainly notice scaling more. But if it’s specced for Hi-DPI, or about 150%, then you probably wouldn’t notice it as much.
Although in the end I say “let it go” if you can’t play the game at maximum detail and the highest resolution.
UPDATE: My blind self noticed there are also major quality differences with the jeep in the background. However, the background is blurred from depth-of-field so it’s likely more exaggerated at lower resolutions.