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Optimal pixel density for external display

S

solitone

macrumors newbie
Original poster
Jan 11, 2019
15
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Apple’s interface design in macOS is set up so it is comfortable for most people at a density of about 110 pixels per inch for non-Retina, and about 220 pixels per inch for Retina — text is readable and button targets are easy to hit at a normal viewing distance. Using a display that isn’t close to 110PPI or 220PPI means text and interface elements will either be too big, or too small.

1636837567462.png


Source: https://bjango.com/articles/macexternaldisplays/

is this thing still relevant today? If I have 160 ppi density, wouldn’t it be possible to scale by 1.5x for instance?

In my MBA M1 default scaling for its retina display is not 2x (in fact it scales to 1440x900). Why would a non integer scaling be a problem with an external display?
 
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Ok. Just wondering now why by default my MBA’s retina display (2560x1600) is non-integer scaled to 1440x900.
 
Even though this results in a slight blurriness and a performance hit?

What I don’t fully grasp is:

- The 220 dpi rule for retina display ensures UI elements are the best size, allowing for a simple integer 2x scaling.
- Apple does not scale by 2x with their built-in retina displays.
 
solitone said:
Even though this results in a slight blurriness and a performance hit?
Click to expand...
I'm able to see the slight blurriness. It doesn't annoy/bother me though, despite me also using monitors that employ "perfect" 2× scaling. As for the performance hit, how noticeable it is depends on low high the scaled resolution is and how powerful your GPU is. The M1's GPU is said to be pretty decent so maybe it's fine (I don't have an M1).

solitone said:
Apple does not scale by 2x with their built-in retina displays.
Click to expand...
It does on all retina iMacs and the new 14"/16" MBPs.
It also does on earlier (2012 to 2015) retina MBPs.

IIRC the 2015 12" retina MacBook was the first Mac to use non-integer scaling by default. All retina MacBooks released after that also did.

In any case, they did this to provide more screen estate.
 
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My issue is that all 4K displays that I know have a pixel density in that red band (picture in original post). I would need a 20” display to have 220 ppi. So non-integer scaling is a must with external displays. Alternatively, I should get a 40” display with a 110 ppi density, and use it in non-retina mode, although as you pointed out in another thread text would be rendered pretty badly.
 
solitone said:
My issue is that all 4K displays that I know have a pixel density in that red band (picture in original post). I would need a 20” display to have 220 ppi.
Click to expand...
The only external 220-ppi "4K" display is the original LG UltraFine 4K (which I happen to have :)).

solitone said:
So non-integer scaling is a must with external displays.
Click to expand...
I also have a display with a pixel density of 163 ppi. I use non-integer scaling with it and it's OK - it's sitting next to two 220 ppi displays running at 2× scaling. There's definitely a visible difference but it's not make-or-break IMO.
 
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Amethyst1 said:
The only external 220-ppi "4K" display is the original LG UltraFine 4K (which I happen to have :)).
Click to expand...
Which is discontiuned, though.

So I’ll have to live with non-integer scaling. How does a 4K 32” screen scaled to 3008x1692 compare to a 4K 27” scaled to 2560x1440? Is text noticibly less sharp considering the greater distance from eyes?
 
solitone said:
I think I’ll get that one. I’ve read several positive posts on the big thread, and I like it.
Click to expand...
Great choice. Here's the thread on it. I run mine scaled to 2560×1707 to get the same simulated PPI as the 27" 5120×2880 monitor (running pixel-perfect 2560×1440) sitting next to it. The additional screen estate is very noticeable and very welcome.
 
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Thanks both- really useful thread.

If I can ask your advice/opinion on something Solitone already mentioned.

I'm running a MBP 14" M1Max through the 5K LG Apple display (27"). (2560x1440 default, so the scaling is not an issue) I'm very lucky to have this display, and while very crisp, but I'm finding the real estate (2560x1440) less than I need for my work. (and I am avoiding running two displays)

So I'm looking for the best 32" display options (the Apple XDR is not an option- just so expensive).
LG32UL950 display comes closest it seems in terms of general reviews, 4K: 3840x2160, but a PPI of 139.9, which seems to be in the danger zone. The real estate gain would be substantial though: I could run it at 3200x1800 (one of the options), which is a sizeable gain in "space".

My concern is that if I run this LG at 3200x1800 the scaling is non-integer and I may face many of the problems discussed (M1 GPU usage uncertainty, blurred text). I haven't managed to find any reviews that deal with this specific issue and how it performs with Macs (M1 or otherwise) under different resolutions. And, for me, it's not very easy to simply access these 32" displays in a shop.

Would enjoy hearing your views or if you know of any good sources on how M1's are performing with scaling external monitors that are not near 220 PPI and 32". Many thanks.

(must say it's disappointing to see how few 32" display options there are today that would match-up easily/well to Apple UI specs, and not cost a fortune. Also, somehow, running a new Mac but on "the same" monitor is strangely deflating)
 
chazoak said:
The real estate gain would be substantial though: I could run it at 3200x1800 (one of the options), which is a sizeable gain in "space".
Click to expand...
What about just running the 5K scaled to 3200×1800? Is that too small for your liking? It would still look better than a 32” “4K” scaled to the same resolution due to the substantially higher ppi.

chazoak said:
must say it's disappointing to see how few 32" display options there are today that would match-up easily/well to Apple UI specs
Click to expand...
There’s virtually no demand for 220 ppi displays outside of the relatively small Mac user base.
 
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Amethyst1 said:
What about just running the 5K scaled to 3200x1800? Is that too small for your liking? It would still look better than a 32” “4K” scaled to the same resolution due to the substantially higher ppi.


There’s virtually no demand for 220 ppi displays outside of the relatively small Mac user base.
Click to expand...
Thanks.
Yes, that's a good idea (27" 5K scaled to 3200). I'm just trying it out now. But I think it will be too small (for my eyes, more than my liking :)) Will give it a few days though.

Yes, good, and sadly true, point. Even within the Mac base, I think the number of users who use their Macs more or less strictly docked is not large. But I would think they are an important base, of developers, and so on. A vocal group I would think.

I think it's a hole in the portfolio, certainly in the level of experience. iPhone, iPad, Mac (non-docked), iMac users enjoy incredibly high quality display experiences, which keep improving. But the lack of affordable displays (27-32") that match Mac-OS scaling preferences (and thus image quality) and/or have Apple Design quality (my LG5K is still a sore sight on my desk) is disappointing. Rumors suggest that they see the hole. Let's see.
Thanks so much for the reply.
 
chazoak said:
Thanks both- really useful thread.

If I can ask your advice/opinion on something Solitone already mentioned.

I'm running a MBP 14" M1Max through the 5K LG Apple display (27"). (2560x1440 default, so the scaling is not an issue) I'm very lucky to have this display, and while very crisp, but I'm finding the real estate (2560x1440) less than I need for my work. (and I am avoiding running two displays)

So I'm looking for the best 32" display options (the Apple XDR is not an option- just so expensive).
LG32UL950 display comes closest it seems in terms of general reviews, 4K: 3840x2160, but a PPI of 139.9, which seems to be in the danger zone. The real estate gain would be substantial though: I could run it at 3200x1800 (one of the options), which is a sizeable gain in "space".

My concern is that if I run this LG at 3200x1800 the scaling is non-integer and I may face many of the problems discussed (M1 GPU usage uncertainty, blurred text). I haven't managed to find any reviews that deal with this specific issue and how it performs with Macs (M1 or otherwise) under different resolutions. And, for me, it's not very easy to simply access these 32" displays in a shop.

Would enjoy hearing your views or if you know of any good sources on how M1's are performing with scaling external monitors that are not near 220 PPI and 32". Many thanks.

(must say it's disappointing to see how few 32" display options there are today that would match-up easily/well to Apple UI specs, and not cost a fortune. Also, somehow, running a new Mac but on "the same" monitor is strangely deflating)
Click to expand...
If you want more space than the 27" 5k displays, want reasonably similar sharpness, and don't want to buy the Pro Display XDR, there's really only the LG 34WK95U-W. I rotate between a 5k iMac in the office and one of these at home, and I may prefer the LG. It's enough larger that I can sit far enough away from it that it seems nearly as sharp as the iMac, yet I run it scaled at 3840x1620 - so a huge gain in working space. It's connected to a new M1 MBP and I'm certainly not noticing negative of scaling in my moderately intense workloads.
 
zhenya said:
If you want more space than the 27" 5k displays, want reasonably similar sharpness, and don't want to buy the Pro Display XDR, there's really only the LG 34WK95U-W. I rotate between a 5k iMac in the office and one of these at home, and I may prefer the LG. It's enough larger that I can sit far enough away from it that it seems nearly as sharp as the iMac, yet I run it scaled at 3840x1620 - so a huge gain in working space. It's connected to a new M1 MBP and I'm certainly not noticing negative of scaling in my moderately intense workloads.
Click to expand...
thanks for sharing
- interesting to see that, despite it being right in the middle of the "red zone" in PPI, you are finding the scaling fine
- 3840 on an 21:9 wide must give a lot of space, and yet not be tiny text. Is that the "default for this display" res?
- have you by any chance tried the 32" LG LG32UL950? Curious how it compared on clarity.
 
chazoak said:
thanks for sharing
- interesting to see that, despite it being right in the middle of the "red zone" in PPI, you are finding the scaling fine
- 3840 on an 21:9 wide must give a lot of space, and yet not be tiny text. Is that the "default for this display" res?
- have you by any chance tried the 32" LG LG32UL950? Curious how it compared on clarity.
Click to expand...
"Default for this display" is 2x pixel doubled at 2560x1080. Everything is comically large to me at that resolution. I have bounced between 3360x1418 and 3840x1620. Either provides plenty of space, frankly. I can easily place 3 full documents/web pages side by side, or have ample space full screen for my creative work.

I have not tried the 32" LG specifically, but have tried other 4k displays in that size range. I find that the ~137ppi is not quite as sharp as I like. The 5k LG has 40% more pixels for just 2" larger display.
 
I would buy two 24in iMacs (24in, 4.5K, 218 ppi) immediately if you could use them as real external displays.
 
Amethyst1 said:
Great choice. Here's the thread on it. I run mine scaled to 2560×1707 to get the same simulated PPI as the 27" 5120×2880 monitor (running pixel-perfect 2560×1440) sitting next to it. The additional screen estate is very noticeable and very welcome.
Click to expand...
My sight is much weaker! I'd rather use its default (1920x1280). Text is sharp, big, and easy to read, although I can't benefit from that additional screen estate.

Great screen BTW, I love it!
 
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zhenya said:
If you want more space than the 27" 5k displays, want reasonably similar sharpness, and don't want to buy the Pro Display XDR, there's really only the LG 34WK95U-W. I rotate between a 5k iMac in the office and one of these at home, and I may prefer the LG. It's enough larger that I can sit far enough away from it that it seems nearly as sharp as the iMac, yet I run it scaled at 3840x1620 - so a huge gain in working space. It's connected to a new M1 MBP and I'm certainly not noticing negative of scaling in my moderately intense workloads.
Click to expand...
Yes, this one is a great one but unfortunately, it has PWM i.e. it flickers with a very low frequency (according to Rtings).
Even if someone is not sensitive I think it's just unnecessary to have, especially considering when someone looks at a monitor for many hours.
 
royas said:
Yes, this one is a great one but unfortunately, it has PWM i.e. it flickers with a very low frequency (according to Rtings).
Even if someone is not sensitive I think it's just unnecessary to have, especially considering when someone looks at a monitor for many hours.
Click to expand...
I have not noticed - perhaps because the monitor is not overly bright at maximum output, and I almost always run it at 100%. I note that many of the other LG monitors of similar price range have the same issue.
 
solitone said:
My sight is much weaker! I'd rather use its default (1920x1280). Text is sharp, big, and easy to read, although I can't benefit from that additional screen estate.
Click to expand...
Well, compared to a 16:9 “4K” monitor running at 1920×1080 HiDPI you’re still getting 18.5% more vertical screen estate. :)
 
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