The subpixel-AA debacle and font rendering

[StellarVixen]

I run 720p x2 on 1080p monitor and it doesn’t heat up at all. You have my screenshot comparison above.


Yes, I lost quite a bit of screen real estate at the expense of more legible fonts and crisp UI rendering, but I adapted.

 

[tornado99]

You may also find a sweet-spot at which everything looks nearly as sharp as true HiDPI. I run a 1440p (2560x1440) monitor at 2048x1152 doubled (so 4096 x 2304). This means that OS X scales up everything x2 to the back buffer, then the GPU scales down everything x0.625 to the screen. Curiously, even though that involves fractional scaling, Apple's magic doesn't make things blurry.

The trick is to use your monitor's pixels to oversample what you are trying to render, but without losing too much screen real estate.

 

[howardroark]

Hi folks!

I have read all posts in this topic. I bought Dell P2421DC (USB-C, 2K) two weeks ago. I am planning to use that monitor with Windows machine, MBP 2017 13'' and Raspberry Pi 4. There is no problem with Windows and Linux but i have problems with MacOS.

But when I connected to Macbook I got a really bad image at 2560x1440 resolution. So, I am tried scaled resolutions tool and I still can't use hidpi at higher resolutions. 1920x1080 is the highest resolution I can use with hidpi. At 1920x1080 resolution, the image is better, but the fonts look a little bad. 1920x1080 is a sufficient resolution for me, but even at this resolution, there are problems with fonts.

The 1600x900 HIDPI resolution fonts and the display are good, but the resolution is very low, making it very useless. Shouldn't I be able to get a good display at least in 1080p on this monitor? 2K monitor insufficient for Macbook?

I do not want to go up to 4k resolution because I use it on other systems. Tomorrow is the last day to refund the monitor, I have to make a decision, so I'm looking for answers to the following questions:

1) My monitor's PPI value is 123. Somewhere I read that a good result can be obtained if the ppi value is close to 110 or 220. So if I refund this monitor and buy a Dell U2720DC or P2720DC, will there be any improvement? (Dell U2720 has 109 PPI scloser to 110 ppi)

2) Is there any way I can use this monitor in 1080p resolution with HIDPI?

3) If someone is successful with Dell 24 or 27 inches, can someone give a model suggestion?

Thank you.

FWIW I’ve managed to track down the cause of the fuzzy text problem and the solution for poor text rendering on non-Retina and non-UHD monitors.

After much searching, encountering much nonsense (e.g. Apple renders fonts so perfectly they only look good on Retina screens etc etc) I finally found the solution - kudos to the serious Geek who figured out how to solve it (links below).

My quick summary:

Each individual monitor has a configuration file.

They are organised by manufacturer (folders) and model (plist files without plist extension) located here:

Macintosh HD⁩ ▸ ⁨System⁩ ▸ ⁨Library⁩ ▸ ⁨Displays⁩ ▸ ⁨Contents⁩ ▸ ⁨Resources⁩ ▸ ⁨Overrides⁩

I don’t know if these are generated by Apple or the display manufacturers.

For various reasons these no longer play well from Mojave onwards.

To get clean text the display must be in Apple’s “HiDPI” mode for the selected resolution.

And there are gotchas: to get a nice 1920 x 1080 resolution, it needs to be configured as double that, 3840 x 2160.

I have same monitor model and I reached the best result with 1600x900 HIDPI. Any chance to share screenshots for 1920x1080? Am I too paranoid? Or have I done something missing?

 

[tornado99]

Hi folks!

I have read all posts in this topic. I bought Dell P2421DC (USB-C, 2K) two weeks ago. I am planning to use that monitor with Windows machine, MBP 2017 13'' and Raspberry Pi 4. There is no problem with Windows and Linux but i have problems with MacOS.

But when I connected to Macbook I got a really bad image at 2560x1440 resolution. So, I am tried scaled resolutions tool and I still can't use hidpi at higher resolutions. 1920x1080 is the highest resolution I can use with hidpi. At 1920x1080 resolution, the image is better, but the fonts look a little bad. 1920x1080 is a sufficient resolution for me, but even at this resolution, there are problems with fonts.

The 1600x900 HIDPI resolution fonts and the display are good, but the resolution is very low, making it very useless. Shouldn't I be able to get a good display at least in 1080p on this monitor? 2K monitor insufficient for Macbook?

I do not want to go up to 4k resolution because I use it on other systems. Tomorrow is the last day to refund the monitor, I have to make a decision, so I'm looking for answers to the following questions:

1) My monitor's PPI value is 123. Somewhere I read that a good result can be obtained if the ppi value is close to 110 or 220. So if I refund this monitor and buy a Dell U2720DC or P2720DC, will there be any improvement? (Dell U2720 has 109 PPI scloser to 110 ppi)

2) Is there any way I can use this monitor in 1080p resolution with HIDPI?

3) If someone is successful with Dell 24 or 27 inches, can someone give a model suggestion?

Thank you.




I have same monitor model and I reached the best result with 1600x900 HIDPI. Any chance to share screenshots for 1920x1080? Am I too paranoid? Or have I done something missing?

I have exactly the same monitor as you but without the USB-C connectivity. If you go back through this thread you shoud be able to create custom HiDPI resolutions that make everything look very decent. As I said, I run at 4096x2304 and everthing is acceptably sharp.

Alternatively, wait for Big Sur, when HiDPI should be enabled automatically.

 

[Minga089]

I have exactly the same monitor as you but without the USB-C connectivity. If you go back through this thread you shoud be able to create custom HiDPI resolutions that make everything look very decent. As I said, I run at 4096x2304 and everthing is acceptably sharp.

Alternatively, wait for Big Sur, when HiDPI should be enabled automatically.

So you basically run it in 20148x1152 HiDPI. I do the same with my P2421DC and imo it's quiet acceptable and the best it's going to get with a 24" QHD monitor in macOS.

 

[howardroark]

So you basically run it in 20148x1152 HiDPI. I do the same with my P2421DC and imo it's quiet acceptable and the best it's going to get with a 24" QHD monitor in macOS.

View attachment 962914

Hi, thank you for the answer.

I am already tried 2048x1152 (HIDPI) but there is still something strange in the image and especially font. Are you using it with a USB-C cable? The PPI of 27 inch 2k Dell monitors is 109, our monitor's PPI is 123. Would it be better if I return this and buy a 27 inch 2k monitor?

This page explains the PPI issue. This source says that if I buy a 27 inch 2k monitor I will get a better result with 109 PPI, right?

I have exactly the same monitor as you but without the USB-C connectivity. If you go back through this thread you shoud be able to create custom HiDPI resolutions that make everything look very decent. As I said, I run at 4096x2304 and everthing is acceptably sharp.

Alternatively, wait for Big Sur, when HiDPI should be enabled automatically.

I am already create custom HiDPI resolutions. 1600x900(HiDPI) is best quality for me but it is very low resolution. So I am trying the get this quality minimum at 1080p.

 

[Minga089]

Hi, thank you for the answer.

I am already tried 2048x1152 (HIDPI) but there is still something strange in the image and especially font. Are you using it with a USB-C cable? The PPI of 27 inch 2k Dell monitors is 109, our monitor's PPI is 123. Would it be better if I return this and buy a 27 inch 2k monitor?

This page explains the PPI issue. This source says that if I buy a 27 inch 2k monitor I will get a better result with 109 PPI, right?

View attachment 962960


I am already create custom HiDPI resolutions. 1600x900(HiDPI) is best quality for me but it is very low resolution. So I am trying the get this quality minimum at 1080p.

If you are still unhappy you can create different HiDPI resolutions yourself and see what works best for you, but I doubt that it will look better than 2048x1152. I've just tested you preferred solution (1600x900 HiDPI) and imo the text is not sharper but only bigger.

I checked the page you've linked and I really don't know what to say. According to this page every 27" 4K Monitor (160 PPI) would fall in the "bad zone" and yet so many people use exactly those type of monitors and are happy. I have seen it myself and in 27" 4K everything looks crystal clear in macOS, especially scaled.

You can try 27" QHD but I am not sure if it really would make that much of a difference. But try it. If that doesn't work for you have to either live with it or go 4K.

EDIT: Yes I use it via USB-C Connection

 

[StellarVixen]

You cannot get HiDPI on non Retina monitor without losing screen real estate. It is impossible.

You have to settle for either less screen real estate or to be content with how fonts and UI look at native resolution.

 

[howardroark]

You cannot get HiDPI on non Retina monitor without losing screen real estate. It is impossible.

You have to settle for either less screen real estate or to be content with how fonts and UI look at native resolution.

Some users have used this monitor and said they are satisfied. Maybe there is something wrong with my monitor or maybe it's a subjective issue. But it was really useless in native resolutions. When I read the articles on a web page, it was really uncomfortable. I just got a good result at 1600x900 HIDPI. I don't need a lot of resolution but 1600x900 was useless as it is a very low resolution. So I just refund the monitor and i am looking for the new options I would be very glad if you have suggestions for 2k. I am thinking of buying a 27 inch 2k monitor.

If you are still unhappy you can create different HiDPI resolutions yourself and see what works best for you, but I doubt that it will look better than 2048x1152. I've just tested you preferred solution (1600x900 HiDPI) and imo the text is not sharper but only bigger.

I checked the page you've linked and I really don't know what to say. According to this page every 27" 4K Monitor (160 PPI) would fall in the "bad zone" and yet so many people use exactly those type of monitors and are happy. I have seen it myself and in 27" 4K everything looks crystal clear in macOS, especially scaled.

You can try 27" QHD but I am not sure if it really would make that much of a difference. But try it. If that doesn't work for you have to either live with it or go 4K.

EDIT: Yes I use it via USB-C Connection

Since there were not many resources, I had to trust in that article. There is a need for a more comprehensive content on the external monitor. As i said above, just i refund the monitor and i am looking for the 2k monitors where i can get a better result. I'm thinking of these two monitors for now:

- Dell U2719DC
- Dell P2720DC

Could the aspect ratio of the screens be causing this problem? Macbook's screen is 16:10 but external monitor is 16: 9

 

[Minga089]

Some users have used this monitor and said they are satisfied. Maybe there is something wrong with my monitor or maybe it's a subjective issue. But it was really useless in native resolutions. When I read the articles on a web page, it was really uncomfortable. I just got a good result at 1600x900 HIDPI. I don't need a lot of resolution but 1600x900 was useless as it is a very low resolution. So I just refund the monitor and i am looking for the new options I would be very glad if you have suggestions for 2k. I am thinking of buying a 27 inch 2k monitor.



Since there were not many resources, I had to trust in that article. There is a need for a more comprehensive content on the external monitor. As i said above, just i refund the monitor and i am looking for the 2k monitors where i can get a better result. I'm thinking of these two monitors for now:

- Dell U2719DC
- Dell P2720DC

Could the aspect ratio of the screens be causing this problem? Macbook's screen is 16:10 but external monitor is 16: 9

No the aspect ratio has nothing to do with it. Just try one of these 27" Dell Monitors, then you know for sure. If they also don't suit you, you have to go 4K. Dell just released a new Budget 4K USB-C monitor: P2721Q
[automerge]1601903951[/automerge]

 

[Farrol]

I want to buy a new 27" monitor for use with several laptops:

- a 2020 MacBook Pro 13"
- a late 2014 MacBook Pro 13"
- a mid 2011 MacBook Air
- and also maybe a new Windows/Unix Laptop

I will use it as an additional screen in conjunction with the laptop screen. Main usage is software development, but occasionally I would edit photos and rarely watch a video.

If I get a 4k model (e.g. Dell UltraSharp U2720Q or the new P2721Q), will it be possible to use it with my older Macs easily?

I guess the 2011 + 2014 GPUs would have difficulties to scale to 5K and then back to 1440p, is this correct?

Is there any way to let the 4k monitor do the scaling for the older Macs and set it up as if it was a 2k/1440p monitor, if you know what I mean?

Or should I forget about 4k and rather buy a 27" 2k monitor with actual 1440p?

 

[howardroark]

Since there were not many resources, I had to trust in that article. There is a need for a more comprehensive content on the external monitor. As i said above, just i refund the monitor and i am looking for the 2k monitors where i can get a better result. I'm thinking of these two monitors for now:

- Dell U2719DC
- Dell P2720DC

Could the aspect ratio of the screens be causing this problem? Macbook's screen is 16:10 but external monitor is 16: 9

Hi, I am looking for a new monitor. I am thinking of buying one of these two models.

- Dell U2719DC: 2k, USB-C port, nice arm.

- LG 27UL550-W: No USB-C port, 4k (but cheaper?).

Can those who know about these monitors comment? There is any scaling problem on 27 inch 4K monitor?

Thanks.

 

[Erehy Dobon]

I have an LG 27UL850-W (with USB-C, DisplayPort). It functions well at 4K ("UI looks like 1920x1080").

I also have a Dell 32" monitor: model S3320DGF QHD 2560x1440p, 165Hz.

If you look at the specs, the LG is a better monitor. However, many Windows apps looked terrible scaled on the LG 4K monitor. I eventually tired of this so I am now using the Dell 32" monitor for both a Mac mini 2018 and a Windows PC. Both are driving this monitor at the native resolution. That means giving up some text sharpness on the Mac because it isn't doing 2x HiDPI text scaling. That's okay by me, my eyes are old and tired plus I don't spend 8+ hours a day staring at computer monitors.

The LG 4K monitor was moved to another room as a backup. It's still a fine monitor, just not ideal to switch between today's Macs and today's Windozes PCs.

One thing for sure, my eyes aren't getting any better and I do appreciate the larger 32" screen size.

Caveat: I am still running Mojave on my Mac.

 

[howardroark]

I have an LG 27UL850-W (with USB-C, DisplayPort). It functions well at 4K ("UI looks like 1920x1080").

I also have a Dell 32" monitor: model S3320DGF QHD 2560x1440p, 165Hz.

If you look at the specs, the LG is a better monitor. However, many Windows apps looked terrible scaled on the LG 4K monitor. I eventually tired of this so I am now using the Dell 32" monitor for both a Mac mini 2018 and a Windows PC. Both are driving this monitor at the native resolution. That means giving up some text sharpness on the Mac because it isn't doing 2x HiDPI text scaling. That's okay by me, my eyes are old and tired plus I don't spend 8+ hours a day staring at computer monitors.

The LG 4K monitor was moved to another room as a backup. It's still a fine monitor, just not ideal to switch between today's Macs and today's Windozes PCs.

One thing for sure, my eyes aren't getting any better and I do appreciate the larger 32" screen size.

Caveat: I am still running Mojave on my Mac.

Hi, thank you for the message.

So what you're saying is that for a 4k monitor it makes more sense to use a monitor larger than 27 inches for using a monitor with native resolution.

Which one do you think will work better between these two models?


- Dell U2719DC: 2k, USB-C port, nice arm.
- LG 27UL550-W: No USB-C port, 4k (but cheaper?).

 

[Farrol]

To test how bad the problem described in this thread actually is I finally upgraded from High Sierra to Mojave.

I have a MacBook Pro 13" mid 2014, external display is Dell 23.5-inch (1920 x 1080), non-retina.

So I was afraid the font rendering would get much worse on the external display, but: I did not notice any degradation. BTW "Font Smoothing" is enabled is system prefs.

So maybe is it just a matter of personal perception that some people have problems with this? I certainly can live with the Mojave rendering on my non-retina display.

Actually I am planning to purchase a new 27" monitor (and a new MacBook Pro). So I guess I could go with non-retina 27" WQHD 1440p, no need to go for 5k or 4k, right?

Fonts on 1440p / 27" should be rendered the same as on 1080p / 23.5", correct?

 

[edubfromktown]

If you are interested in a non usb-c port display, the AOC U2790VQ 27" 4k UHD is quite nice and works well with Mac's. It was $243 yesterday and has gone back up to $269. (If you are an Amazon Prime customer, there may be a deal on them October 13-14).

Even @$269, it is a good deal in my opinion. It has HDMI or Display Port (the latter may be preferred if you want to daisy chain multiple displays together).

 

[tornado99]

Anybody about to install Big Sur want to do some pixel level comparisons of font rendering between Catalina and Big Sur?

Apple does seem to do some undocumented tweaking with each new version even if this time its from grayscale AA to grayscale AA. Would be interesting to see if anything's changed.

 

[cmhsam]

I can tell you I been running BS BETA since day 1 and the fonts look much cleaner on external displays especially when connected to my u3419w. Today I booted back into Catalina and noticed a difference.
I assume Apple has made some updates

 

[ugh]

Anybody about to install Big Sur want to do some pixel level comparisons of font rendering between Catalina and Big Sur?

Apple does seem to do some undocumented tweaking with each new version even if this time its from grayscale AA to grayscale AA. Would be interesting to see if anything's changed.

I just installed Big Sur on my 15" retina macbook pro, and it looks like crap. All fonts are blurry. Of course, they are rendered blurry with grayscale fringing on what should be sharp lines. The previous hacks from Catalina do not work. I threw out my last non-retina display, but this is still not good enough.

Just to point out that it is very difficult to take a real pixel level screenshot, Apple cheats here and substitutes in a differently rendered image. This even happens on the digital color meter for font rendering sometimes, even in Catalina. It will sample a different framebuffer than the one displayed.

My assumption is the same brain damaged engineers that designed the new flat ui also have severe nearsightedness from not being allowed outside as children, and can't even tell the fonts are blurry - no matter what "retina" label is attached to their displays.

Windows now seems the last refuge of good font rendering. What has the world come to?

 

[tornado99]

I just installed Big Sur on my 15" retina macbook pro, and it looks like crap. All fonts are blurry. Of course, they are rendered blurry with grayscale fringing on what should be sharp lines. The previous hacks from Catalina do not work. I threw out my last non-retina display, but this is still not good enough.

Just to point out that it is very difficult to take a real pixel level screenshot, Apple cheats here and substitutes in a differently rendered image. This even happens on the digital color meter for font rendering sometimes, even in Catalina. It will sample a different framebuffer than the one displayed.

My assumption is the same brain damaged engineers that designed the new flat ui also have severe nearsightedness from not being allowed outside as children, and can't even tell the fonts are blurry - no matter what "retina" label is attached to their displays.

Windows now seems the last refuge of good font rendering. What has the world come to?

I understand that the previous hack to get "supersampling" i.e. a larger framebuffer than the physical resolution of your screen was now disabled because Big Sur automatically allows selection of those modes in the Display Preferences even when using e.g. a Dell monitor? Unless, of course, Apple has decided to make that only available for "official" monitors like the LG Ultrafine and Apple Display....

The best way to do a pixel-level analysis is hold your smartphone about 10cm from the screen and take a photo of some text.

Actually, I find that Linux has the best font rendering as they use the now patent-free Cleartype everywhere, whereas Windows has partially regressed to using grayscale AA in major applications like Office!

Also @theorist9 what is your opinion on Mojave with sub-pixel AA hack vs Catalina? Currently I am considering downgrading from Catalina to get back the font quality. High Sierra is a no-go due to certain apps I run. Looking back through the pages of this thread it seems that Mojave is the worst of both worlds (not very good color AA and unoptimised grayscale AA). Is that accurate?

 

[ugh]

Actually, I find that Linux has the best font rendering as they use the now patent-free Cleartype everywhere, whereas Windows has partially regressed to using grayscale AA in major applications like Office!

Only if you use infinality and do hand tuning. It's not good out of the box, and uses very large fonts to compensate. Its weakness is when using small fonts.

 

[tornado99]

Only if you use infinality and do hand tuning. It's not good out of the box, and uses very large fonts to compensate. Its weakness is when using small fonts.

Actually the latest version of Freetype (released last month) has Cleartype turned on by default, so should apply to all distros going forward with no hand tinkering required. The worthy parts of Infinality were incorporated into Freetype over the previous couple of years. So as of now it is very good out of the box. Small fonts look excellent to me.

 

[meteoreos]

As someone who's currently using the supersampling hack on Catalina (Dell U2520D), it's not worth upgrading to Big Sur?

 

[tornado99]

As someone who's currently using the supersampling hack on Catalina (Dell U2520D), it's not worth upgrading to Big Sur?

If they've disabled supersampling on non-Apple monitors then definitely not. Also, seems to be many people saying that UI contrast is lower and the font size used for many OS elements is smaller. None of which make for a positive reason to upgrade. The only push factor would be if they've managed to squeeze a bit more sharpness out of grayscale-AA. Personally, I'll probably skip Big Sur.

 

[meteoreos]

If they've disabled supersampling on non-Apple monitors then definitely not. Also, seems to be many people saying that UI contrast is lower and the font size used for many OS elements is smaller. None of which make for a positive reason to upgrade. The only push factor would be if they've managed to squeeze a bit more sharpness out of grayscale-AA. Personally, I'll probably skip Big Sur.

That is a shame. I'll probably not update either in that case.