[kirill5pol]

I’m pretty sure the parent knows that MacOS doesn’t support “true retina” at 4K 27” (at a reasonable size). The way MacOS handles resolution (that’s not perfect 1x or 2x scaling) is by rendering at twice the resolution you selected in settings and then downscaling to the true resolution of the monitor. So if you want to render at 1440p you render at 5k then downscale to 4K. What I believe the parent was trying to get across is that 5k downscaled to 4K looks better than true 1440p. Although it does tax the GPU more, many people would agree it’s worth it over 1440p.

[yeahgoodok]

I feel like the 'shimmering' when scrolling on 27@4k would drive me nuts. But to each their own.

[6a74]

In macOS there are side effects of scaling though, notably "blurry pixels," "shimmering," and increased GPU usage.

[pivo]

I haven't noticed any of those issues and I've been using a variety of Macs (2013 MBP 15", 2019 MBP 13", 2019 MacMini, 2013 MacPro) with a variety of 27" and 32" 4K monitors for over a year now. The 27" 4K monitors are for me the perfect compromise between screen real estate and display quality.

I definitely don't notice blurry pixels. I don't game, so maybe that's why I don't notice increased CPU use.

[alisonkisk]

1440p (2560x1440) is 5K pixel-doubled. (27" iMac)

1080p is 4K pixel-doubled (21.5" iMac) (or 5K downscaled and pixel-doubled).