I still don't understand how 27" 4k monitors work with macOS - can someone explain it to me please?

[g35]

I have read a lot about how it's a terrible idea to purchase a 27" 4k monitor for a Mac. The idea being that a 24" 4k or 27" 5k or even 27" 1440p would be much better, but I can't figure out exactly the issue with 27" 4k set to 2x scaling.

Let's say a 27" 1440p or 5k screen (set to "looks like 2560 x 1440") both display the macOS menubar as 6 mm tall, just much more crisp on the 5k monitor.

And let's say the 27" 4k monitor (set to "looks like 1920 x 1080") displays the same menubar as 8 mm tall, and I am ok with that. Imagine I don't mind all the fixed-size on-screen elements being slightly bigger on the 27" 4k vs the 27" 5k.

Aside from the obvious loss of some pixels/clarity going from 5k to 4k, and assuming the available screen real estate is ok with me, do I lose anything at all by getting a 27" 4k monitor (that's set to "looks like 1920 x 1080")? It should very, very crisp, right, like pixel perfect? More so than the 1440p screen, since it's still using perfect integer scaling? No performance penalty or blurriness??

This is a sincere question since like I said I have seen so much ink spilled about the terribleness of 27" 4k monitors, but if one is ok with the bigger size of elements/less screen real estate when set to "looks like 1920 x 1080", I want to make sure I am not missing out on something else.

I had set my brother's 27” 5k iMac set to “looks like 2048 x 1152,” which is fairly close to 1920 x 1080, and the size of the elements/available screen real estate was just fine for me. So that's why I would like to make sure I can still get pixel-perfect clarity on a 27" 4k screen with "looks like 1920 x 1080," and not the blurry mess some people say they are getting.

Thanks

 

[roman.stapunov]

I use 4k 27” at looks like 1440p scale and have no issues. I had 1440p 27” before and 4k 27” much better to work with. I know that graphics designers may have issues due to missed pixels when 2x scale isn’t used, but personally I think that issue is overblown

 

[EastHillWill]

Maybe I'm misremembering, but it seems like many folks have a fundamental issue with the PPI of a 27" (or larger) 4k desk monitor, all other things aside. They feel that 4K is only acceptable up to about 24", beyond which they want 5K, etc.

Personally, I'm okay with 4K on a 27" screen, although that's my personal PPI floor. 4K at 32" doesn't look to me, but many folks are just fine with it. Absolutely a personal preference thing.

 

[G5isAlive]

I own and have side by side while working, Apples 5k Studio display, and an LG HDR 4k monitor. Both are 27 inch.

It's a long answer to end up with, the 4k will work fine for you regardless of the scale you chose. If you start with a good 4k. The 5k is better, but comes with a price tag.

The 4k defaults to 1920 x 1080, so the standard 2x, and I suppose one could argue a 1080p would work as well (and be cheaper), but my LG is bright, and sharp, and even at 1080p looks better than a cheap 1080p (which I have as well). Having said that, I DO scale it to 2560 x 1440 and sometimes to 3008 x 1692, and it works and looks good. Repeat, it scales fine.

Now the 5k I have on default which is 2560 x 1440. So side by side is my 5k and 4k and both at 2560 and 1440. Yes, the studio display looks better if I focus on it. Brighter. Tad crisper.

I do my graphics work on the 5k. I think the color accuracy is better, and no risk of lost pixels, and I have all my text based applications (word processor, calendar email) on my 4k to the side. But honestly as I work during my day, I dont sit here saying, dang that 4k looks bad. It looks fine. Even sitting next to my 5k.

Thats just my subjective I dont care what the numbers say perspective. I think too many people get caught up on specs. Does it work or doesn't it?

 

[g35]

I own and have side by side while working, Apples 5k Studio display, and an LG HDR 4k monitor. Both are 27 inch.

It's a long answer to end up with, the 4k will work fine for you regardless of the scale you chose. If you start with a good 4k. The 5k is better, but comes with a price tag.

The 4k defaults to 1920 x 1080, so the standard 2x, and I suppose one could argue a 1080p would work as well (and be cheaper), but my LG is bright, and sharp, and even at 1080p looks better than a cheap 1080p (which I have as well). Having said that, I DO scale it to 2560 x 1440 and sometimes to 3008 x 1692, and it works and looks good. Repeat, it scales fine.

Now the 5k I have on default which is 2560 x 1440. So side by side is my 5k and 4k and both at 2560 and 1440. Yes, the studio display looks better if I focus on it. Brighter. Tad crisper.

I do my graphics work on the 5k. I think the color accuracy is better, and no risk of lost pixels, and I have all my text based applications (word processor, calendar email) on my 4k to the side. But honestly as I work during my day, I dont sit here saying, dang that 4k looks bad. It looks fine. Even sitting next to my 5k.

Thats just my subjective I dont care what the numbers say perspective. I think too many people get caught up on specs. Does it work or doesn't it?

Thanks for sharing your experience. That's helpful

 

[Zest28]

The real question should be, do you want your external display look like your iPhone, iPad and MacBook Pro displays? If yes, get the Apple Studio Display.

If not, get a much cheaper 4K display.

 

[jdb8167]

I have read a lot about how it's a terrible idea to purchase a 27" 4k monitor for a Mac. The idea being that a 24" 4k or 27" 5k or even 27" 1440p would be much better, but I can't figure out exactly the issue with 27" 4k set to 2x scaling.

Let's say a 27" 1440p or 5k screen (set to "looks like 2560 x 1440") both display the macOS menubar as 6 mm tall, just much more crisp on the 5k monitor.

And let's say the 27" 4k monitor (set to "looks like 1920 x 1080") displays the same menubar as 8 mm tall, and I am ok with that. Imagine I don't mind all the fixed-size on-screen elements being slightly bigger on the 27" 4k vs the 27" 5k.

Aside from the obvious loss of some pixels/clarity going from 5k to 4k, and assuming the available screen real estate is ok with me, do I lose anything at all by getting a 27" 4k monitor (that's set to "looks like 1920 x 1080")? It should very, very crisp, right, like pixel perfect? More so than the 1440p screen, since it's still using perfect integer scaling? No performance penalty or blurriness??

This is a sincere question since like I said I have seen so much ink spilled about the terribleness of 27" 4k monitors, but if one is ok with the bigger size of elements/less screen real estate when set to "looks like 1920 x 1080", I want to make sure I am not missing out on something else.

I had set my brother's 27” 5k iMac set to “looks like 2048 x 1152,” which is fairly close to 1920 x 1080, and the size of the elements/available screen real estate was just fine for me. So that's why I would like to make sure I can still get pixel-perfect clarity on a 27" 4k screen with "looks like 1920 x 1080," and not the blurry mess some people say they are getting.

Thanks

It seems like you understand correctly. With a 27" 4K display you get about 163 PPI. With a 27" 5K display you get about 218 PPI. I compromised personally and went with a 24" 4K display that gets about 185 PPI. It is noticeably less resolution than my M2 MacBook Air's display but if I don't use them side-by-side, I really don't notice.

 

[antipodean]

OP you have summarized everything correctly. I have a 32" 4K (Dell Ultrasharp) for my M1 Mac mini and a Studio Display (27" 5K) for my M1 Max 16" MBP.

In my experience 2x retina (i.e. integer scaling) is a little nicer than any non-integer scaling, but it is not night & day. Apple Silicon GPUs handle the non-integer scaling without difficulty (i.e. performance penality is small) and the reduction in sharpness is noticeable, but not severe.

You would certainly have a nice sharp desktop running a 4K display at "looks like 1920x1080". Most folks would say the UI elements are too big at that scaling, however. Obviously YMMV. I tend to run my 32" 4K at "looks like 2560x1440", but I have experimented with the 1080 lookalike.

To some extent this is about expectations. If you use your external display alongside a modern retina Apple display (e.g. MBP's built-in display), you really need something like the Studio Display to make a perfect match.

TLDR: 4K is fine, but 5K is even finer.

 

[mlody]

A regular 1440p screen won't be as sharp as the scalled 5K display, cause 5K display will have significantly more pixels to render the same output. I went from 27" 5K iMac to 27" Dell UltraSharp. If you put them side by side, you will notice the difference if you look hard, but once start using 1440p monitor, you will get used to that quick too.

 

[staypuftforums]

A regular 1440p screen won't be as sharp as the scalled 5K display, cause 5K display will have significantly more pixels to render the same output. I went from 27" 5K iMac to 27" Dell UltraSharp. If you put them side by side, you will notice the difference if you look hard, but once start using 1440p monitor, you will get used to that quick too.

For text and UI, yes. It’s a major improvement. But for sub-4K video playback in full screen, no. It’s actually a downgrade. Maybe this can be fixed with software improvements in the future, but today’s Mac monitors have really bad up-scaling.

Recently bought a 4K iMac (2019) and it’s pretty rough watching anything besides 4K content, which looks incredible.

On YouTube for example, I only go full-screen if the content is 4K. If not, I watch on the website’s embedded player.
720p video will look mostly fine on a 1080p monitor. But looks horrible on 4K monitor. Even 1080p looks somewhat bad.

4K monitors have 4x as many pixels as a 1080p monitors, so 1080p video gets stretched to the point that it loses a lot of the finer detail. Everything ends up looking soft and blurry, unless you scale down the video to roughly 1/4 of the screen’s size.

 

[Aggedor]

I don't quite understand this thread. I have an M1 MBA, connected to a 27" 4K LG display. My Displays setting is on the middle option. The Graphics/Displays section of the System Report tells me the resolution is 5120 x 2880, and the UI is 2560 x 1440 (because macOS renders the display at 5K then pixel doubles to display it at 2560 x 1440).

The display looks perfect to me. Everything is super sharp, and there is no performance hit from the UI scaling. 4K video plays fine.

 

[MajorFubar]

How it works? I plugged it in and a picture appeared.
Though not instantly because it turns out HDMI to HDMI is a big no-no between M-series Macs and Samsung monitors.
The key to my happiness is I don't get ridiculously anal about scaling or resolution.
If a picture appears, and I can read the screen clearly, all is good.
If I can't read the screen clearly, I reduce the resolution to make stuff bigger.
Funny how it can literally be that simple.

 

[EzisAA]

LG 23,7 inch 4K Thunderbolt 3 monitor is great choice, if you don't want spend money for Studio Display. Same color calibrated from factory is Apple built displays.

2x Thunderbolt 3 ports
3x USB-C 5Gb/s ports
2m Thunderbot 3 cable 40Gb/s
1,5m Thunderbolt 3 cable 20Gb/s (or USB 10Gb/s)
Speakers (not the best, but for price is ok, better than nothing)
Work like Apple Display, but look like LG monitor.

If your mac support two external displays, then you can daisy-chain two monitors by the Thunderbolt.