27" Monitor - 1440p or 4k?

[SteelBlueTJ]

I currently run a Dell U2717D 1440P monitor with my M1 Mac Mini. It works great but no USB-C connectivity. I was thinking about getting the LG 27UK850 4K monitor and then use my Dell as a secondary display maybe in portrait mode. Would I notice a difference in 4k vs 1440p at 27 inches? I read that many scale down to 1440p anyway so would the upgrade even be worth it? I don't game. It would mainly be used for photography, internet browsing, word processing. Sharp text is important to me. Thanks

 

[Amethyst1]

Would I notice a difference in 4k vs 1440p at 27 inches?

Very likely. Text rendering is much better on “4K” monitors than on 1440p ones on macOS. This also applies if the “4K” is scaled to look like 1440p. If you want sharp text you need a “4K” or higher-resolution monitor.

 

[Aggedor]

Yep, 4K for sure. macOS's rendering below this is awful. 4K scaled to the middle setting ("looks like 2560 x 1440p) will give you true pixel doubling (macOS internally renders that res in 5K then scales it down exactly 2:1).

 

[Amethyst1]

4K scaled to the middle setting ("looks like 2560 x 1440p) will give you true pixel doubling (macOS internally renders that res in 5K then scales it down exactly 2:1).

Only 1920×1080 HiDPI is pixel-doubled on “4K”.
Downscaling a 5K framebuffer for outputting to a “4K” monitor isn’t 2:1 — it’s 1.778:1 and introduces a slight but visible (to me) blurriness.
If you want pixel-doubled 2560×1440 you need a 5K monitor.

 

[Aggedor]

Only 1920x1080 HiDPI is pixel-doubled on “4K”.
Downscaling a 5K framebuffer for outputting to a “4K” monitor isn’t 2:1 — it’s 1.25:1 and introduces a slight but visible (to me) blurriness.
If you want pixel-doubled 2560x1440 you need a 5K monitor.

It is 2:1 - 5K is 5120 × 2880. 2560 x 1440 is exactly half the resolution.

 

[Amethyst1]

It is 2:1 - 5K is 5120 × 2880. 2560 x 1440 is exactly half the resolution.

5120×2880 is four times as many pixels as 2560×1440, so it’s 4:1. Running 2560×1440 HiDPI on a “4K” monitor downscales a 5120×2880 framebuffer to a 3840×2160 monitor.

 

[Fishrrman]

OP wrote:
"I currently run a Dell U2717D 1440P monitor with my M1 Mac Mini. It works great but no USB-C connectivity."

If it "works great", I'd forget about USBc and just keep using it.
Get a USBc hub, or something...

Old saying applies:
"If it ain't broke, don't 'fix' it..."

 

[MikeDr206]

At home I have a Dell UP2715K 5K monitor. When I visit my mom in Az for weeks at a time, I use her 27“ Apple Cinema Display which is 1440p.

Of course the 5K is superior. But after a day or so using the 1440p, i don’t mind it at all. My rMB 12” runs Big Sur. The only issue with lack of resolution is when reading very small text.

 

[Amethyst1]

My rMB 12” runs Big Sur.

I hope you’re not running the UP2715K from that — because it’s limited to “4K”.

 

[MikeDr206]

I hope you’re not running the UP2715K from that — because it’s limited to “4K”.

Correct! At home I use a 2018 Mac Mini. It acts as a Time Machine backup server so it’s on all the time.

and perhaps TMI, but my assistant and I use Resilio Sync to sync work files back and forth. The MM is always on so that when she changes a file and then turns off her MBP, it'll sync to the MM so when I turn on my rMB I’ll be able to get the synced file from the MM.

resilio is just awesome. Totally rock solid, even when there is a super poor Internet connection (hotel, LTE hot spot, etc).