4K vs 5K if running scaled resolution

[reuptake]

I'm looking for a new display to replace my ageing iMac 27". I installed BetterDisplay and I'm finding 2304x1296 more comfortable for my eyes than "native" resolution. I don't see much difference in text sharpness to be honest.

I was thinking of buying 5K 27" display as a direct replacement but I started to wonder if it's worth extra money if I will still run it mostly at scaled resolution? Maybe I should consider 4K 27" scaled to similar resolution would be OK for me? Especially when taking into account that there are some 120Hz 4K displays.

Has anyone compared "upscaled" 4K to "downscaled" 5K?

 

[DankeBrutus]

IIRC the way macOS scaling works a 4K display natively scales to look like 1080p.

5K 16:9 (5120x2880) scales to 1440p (2560x1440)
4K 16:9 (3840x2160) scales to 1080p (1920x1080)

Pixel count:

5K	14,745,600
1440p	3,686,400
4K	8,294,400
1080p	2,073,600

edit: reply was posted before I was done...

A 4K display has a PPI of 163 at 27" versus the 220 PPI of 5K 27" (assuming 16:9). Basically, the UI will look larger on a 4K panel at default scaling compared to a 5K panel. I can't speak much on the quality of that scaling but the brief time I've used macOS on a 4K screen has looked good, but that was on a TV so I was sitting further away than I would a monitor.

 

[reuptake]

IIRC the way macOS scaling works a 4K display natively scales to look like 1080p.

5K 16:9 (5120x2880) scales to 1440p (2560x1440)
4K 16:9 (3840x2160) scales to 1080p (1920x1080)

Yes, this is default native scaling (and as a result everything is large on 4K)

But my question was: if I prefer 2304x1296 on 5K then maybe it's possible to scale 4K to similar resolution

 

[DankeBrutus]

Yes, this is default native scaling (and as a result everything is large on 4K)

But my question was: if I prefer 2304x1296 on 5K then maybe it's possible to scale 4K to similar resolution

My bad, if no one else jumps in I can download BetterDisplay on my MacBook and hook it up to my TV tonight after work. In my limited experience BetterDisplay was much better at allowing arbitrary, for lack of a better word, resolution scaling. I can confirm if 2304x1296 is an option with a 4K panel.

edit: a word

 

[alfogator]

Yes, this is default native scaling (and as a result everything is large on 4K)

But my question was: if I prefer 2304x1296 on 5K then maybe it's possible to scale 4K to similar resolution

Yes you can scale both to any resolution you want. 5K will be sharper of course.

MacOS first renders at double your target resolution (4608 horizontal in your case) and then resamples to the hardware monitor native resolution using a high quality filter (lanczos or equivalent) to preserve sharpness.
This makes the result pretty good, still worse than an unscaled image and 5K will look better than 4K.
If that difference does matter to you is something only your eyes can tell. Many people don't mind it (I have worked for years on 4K resampled), others consider it unacceptable.

 

[Bigwaff]

If you haven't read, these posts are very informative...

MacOS scaling, HiDPI, LoDPI explanation

Unlock your displays on your Mac! Flexible HiDPI scaling, XDR/HDR extra brightness, virtual screens, DDC control, extra dimming, PIP/streaming, EDID override and lots more! - waydabber/BetterDisplay

github.com

Fully scalable HiDPI desktop

Unlock your displays on your Mac! Flexible HiDPI scaling, XDR/HDR extra brightness, virtual screens, DDC control, extra dimming, PIP/streaming, EDID override and lots more! - waydabber/BetterDisplay

github.com

 

[StevenJobsJr]

A lot of this is down to the person. Some people can't tell the difference between 60Hz and 120Hz, yet others swear they can feel the difference between 185Hz and 240Hz. Same for scaled resolutions.

 

[maflynn]

Consider a tool called BetterDisplay. It doesn't improve the scaling quality (something I feel macos does poorly) but allows many more options to help dial in a given resolution that works best for you.

For instance, on my 4k monitor I run 2048x1152, I get less screen real estate in macos then in Linux and windows and dare I say less crispness/clarity

 

[poorcody]

To answer your question, no scaling a 4k 27" display is not going to look as good as 5k 27". Because the 5k is at 220 DPI, the text will look good at whatever resolution you choose. But the lower 163 DPI of the 4k means not going with the native resolution or possibly even scales will make things not crisp.

This was the whole idea of a "Retina" screen -- when you get a high-enough pixel density (>200 dots per inch) -- the eye can't distinguish individual pixels so all resolutions will look good.

 

[meson]

If your eyes are at the point where going to a scaled resolution to help with the text size matters, I doubt the difference in pixel density between 27" 4k and 5k monitors will be a sticking point.

I use an inexpensive LG 32" 4k monitor. The colors seem fine to me next to my M1 MacBook Pro, but they don't pop the same way due to being a matte screen vs glossy. I tend to run in full 4k resolution. Scaled resolutions above looks like 1920x1080 look good enough to me. What many will claim is the best mode to run in due to pixel doubling, "looks like 1920x1080," looks like absolute garbage to me at my normal viewing distance.

This is one of those things where there are trade offs. If you've been around computers since the days before retina displays became a thing, I think you'll find that a 27" 4k monitor is quite impressive all things considered, even running in a scaled mode.

 

[reuptake]

Thanks for all the replies, although it seems that some of them miss what I wrote (or I was not precise).

I am using Better Display right now to downscale resolution on my current 5K so I won't be comparing upscaled 4K with 5K, but with downscaled 5K.

If you've been around computers since the days before retina displays became a thing, I think you'll find that a 27" 4k monitor is quite impressive all things considered, even running in a scaled mode.

I've been around for such a long time that I remember connecting computers to home TV, but this means that my eyes are quite old. On the other hand I'm quite used to retina 27" iMac...