M1 Mac mini won't recognize manual HiDPI settings

[sunsetrunner]

I recently upgraded my desktop setup to a new M1 Mac mini. Pretty good so far, without any hardware issues. Only problem is with forced HiDPI settings for one of my monitors which I never had any issues on my previous setup.

I'm using two monitors. They both support HDMI&Type-C inputs and I can swap connections without any issues. They're very crisp and sharp screens, with very high PPIs.

15.6" 4K monitor through USB-C (mounted horizontally if it matters)
12.5" 2K monitor (mounted vertically if it matters)

4K monitor supports native HiDPI even on M1 Mac Mini and it's easy to adjust its DPI to please my eyes through Display Settings or RDM menu bar tool. But 2K monitor doesn't have native HiDPI support on M1 Mac mini. I executed DisplayResolutionEnabled command on Terminal and tried to force HiDPI settings for it which previously on my Intel Macs it was easy to adjust any screen's DPI value to my liking through Display Settings (holding shift key while choosing scaled resolutions) or using RDM. But M1 Mac mini won't recognize these forced HiDPI settings whatever I tried. On all my previous Macs I used to apply these manual settings on any external monitor and never had any issues.

I found some tips on Reddit and GitHub to override PropertyList file for a specific display on Big Sur but they also didn't solve the problem. So my issue looks like related to M1 architecture not Big Sur. Anyone has the same problem or any suggestions?

 

[chabig]

It might not be working because your displays have USB interfaces. The Mini really wants to put out video over HDMI and Thunderbolt interfaces. Your best bet for the troublesome display might be a USB-C to HDMI adapter.

 

[fabdub]

It just doesn't work for now ... everyone is experiencing the same issue.
I am in that boat. Sorry !!!!

 

[sunsetrunner]

It might not be working because your displays have USB interfaces. The Mini really wants to put out video over HDMI and Thunderbolt interfaces. Your best bet for the troublesome display might be a USB-C to HDMI adapter.

Both displays have HDMI & USB-C (Thunderbolt 3) ports and I’ve tried all possibilities with appropriate cables. This more looks like a common issue with M1’s GPU regarding displays.

 

[jabbr]

also experiencing this with my M1 MBP. I'd like to run my 25" 2K monitor scaled up a bit like I do on my desktop Mac.

 

[itsphilgeorge]

I recently upgraded my desktop setup to a new M1 Mac mini. Pretty good so far, without any hardware issues. Only problem is with forced HiDPI settings for one of my monitors which I never had any issues on my previous setup.

I'm using two monitors. They both support HDMI&Type-C inputs and I can swap connections without any issues. They're very crisp and sharp screens, with very high PPIs.

15.6" 4K monitor through USB-C (mounted horizontally if it matters)
12.5" 2K monitor (mounted vertically if it matters)

View attachment 1686003

4K monitor supports native HiDPI even on M1 Mac Mini and it's easy to adjust its DPI to please my eyes through Display Settings or RDM menu bar tool. But 2K monitor doesn't have native HiDPI support on M1 Mac mini. I executed DisplayResolutionEnabled command on Terminal and tried to force HiDPI settings for it which previously on my Intel Macs it was easy to adjust any screen's DPI value to my liking through Display Settings (holding shift key while choosing scaled resolutions) or using RDM. But M1 Mac mini won't recognize these forced HiDPI settings whatever I tried. On all my previous Macs I used to apply these manual settings on any external monitor and never had any issues.

I found some tips on Reddit and GitHub to override PropertyList file for a specific display on Big Sur but they also didn't solve the problem. So my issue looks like related to M1 architecture not Big Sur. Anyone has the same problem or any suggestions?

View attachment 1686011

This is an issue with how Apple is handling scaled resolutions on the Apple M1. I currently am working with Apple to try and find a resolution, but essentially it looks like there are fewer options when using scaled mode than we previously enjoyed!

I will update people on my progress over here:

https://forums.macrumors.com/threads/m1-mbp-lg-34-inch-ultra-wide-5k2k.2267299/

Let me know if you get anywhere.

Cheers.

 

[ftor1]

4K monitor supports native HiDPI even on M1 Mac Mini and it's easy to adjust its DPI to please my eyes through Display Settings or RDM menu bar tool. But 2K monitor doesn't have native HiDPI support on M1 Mac mini. I executed DisplayResolutionEnabled command on Terminal and tried to force HiDPI settings for it which previously on my Intel Macs it was easy to adjust any screen's DPI value to my liking through Display Settings (holding shift key while choosing scaled resolutions) or using RDM. But M1 Mac mini won't recognize these forced HiDPI settings whatever I tried. On all my previous Macs I used to apply these manual settings on any external monitor and never had any issues.

I have an ultra-wide LG 29um69g (2560x1080) with a new M1 Mac mini and I'm not satisfied with text sharpness and overall smoothness of the system. I've tried to configure Hidpi via SwitchResX and RDM but it didn't work.
Did I understand right that hidpi will work fine with any 4K non ultra-wide display?

 

[JCG_80]

Same here have a DELL U2520D Ultra sharp (2560x1440) and the text is terrible, even after eventually getting the M1 to sync with RGB. SwitchResX does not work for custom res and I see no fixes through terminal that have worked or improved. Maybe Apple will fix this, maybe they wont. Its unknown but the M1 is going back today because I want to use external displays with the M1 Air. Never have I experienced resolution issues like this! Even on Ubuntu! I may even buy an Intel MAC since I could setup custom res with SwitchResx at least.

 

[AlphaCentauri]

The problems you have with text clarity have nothing to do with M1. It’s the way text is being rendered on non HiDPI displays since Catalina I think. Apple just don’t care much about font aliasing on low DPI displays. Changing to Intel will not help, changing display to 4K or more will help, because Mac OS then can use HiDPI modes and the text will look sharp.

 

[JCG_80]

I sent mine back today. TBH - If I cant use QHD monitor out of the box, where all other OS/systems can without giving me huge headaches, then its no use to me as good as it is!! I was very impressed with the M1 but this is for me is a sticking point. I'm on my third monitor but didnt try 4K one. The U2520D Dell monitor has a higher PPI of 117 but if thats not good enough still I'm not interesting in trying a 4th, 5th or 6th monitor just to get an acceptable display. Apple should/must have better UAT for the wider market not just what they "think" is acceptable.

 

[AlphaCentauri]

I have an ultra-wide LG 29um69g (2560x1080) with a new M1 Mac mini and I'm not satisfied with text sharpness and overall smoothness of the system. I've tried to configure Hidpi via SwitchResX and RDM but it didn't work.
Did I understand right that hidpi will work fine with any 4K non ultra-wide display?

Ideal HiDPI is reducing number of pixels both horizontally and vertically by half so 4K HiDPI “looks like” 1080p but it’s super sharp. In your case, if HiDPI resolution would be available, 2560x1080 would “look like” 1280x540, so completely unusable.

i have LG 5K2K and I use it in HiDPI mode which “looks like” 2560x1080 but everything is sharp and text looks great. I sit fair distance from the screen so this is perfect resolution for me.

Please remember that to have HiDPI resolution, the actual resolution of display should be ideally at least 2x bigger both horizontally and vertically than desired “looks like” resolution.

 

[ftor1]

Ideal HiDPI is reducing number of pixels both horizontally and vertically by half so 4K HiDPI “looks like” 1080p but it’s super sharp. In your case, if HiDPI resolution would be available, 2560x1080 would “look like” 1280x540, so completely unusable.

i have LG 5K2K and I use it in HiDPI mode which “looks like” 2560x1080 but everything is sharp and text looks great. I sit fair distance from the screen so this is perfect resolution for me.

Please remember that to have HiDPI resolution, the actual resolution of display should be ideally at least 2x bigger both horizontally and vertically than desired “looks like” resolution.

I'll be fine with 1080p if it's ultra sharp. So should it work with any true 4K display (3840 × 2160)?

 

[AlphaCentauri]

I'll be fine with 1080p if it's ultra sharp. So should it work with any true 4K display (3840 × 2160)?

Yes, HiDPI will “look like” 1920x1080 then. Or you can go for MSI or LG 5K2K display and then HiDPI will “look like” 2560x1080 but sharp (if you prefer UW screen aspect).

 

[ftor1]

Yes, HiDPI will “look like” 1920x1080 then. Or you can go for MSI or LG 5K2K display and then HiDPI will “look like” 2560x1080 but sharp (if you prefer UW screen aspect).

Thanks! Your answer is extremely useful

 

[outdevo]

Just in case anyone was looking for a headless M1 Mac Mini solution for HiDPI via remote desktop (knowing that you can't workaround it with SwitchResX, e.g.), I found that this "dummy" dongle works great on the M1.

BUYMINERS.CA 4K HDMI Dummy Plug - Virtual Monitor Display Emulator, Headless Display Adapter Supports up to 3840x2160@60Hz, 1080@120Hz DVI EDID Emulator (Single)

BUYMINERS.CA 4K HDMI Dummy Plug - Virtual Monitor Display Emulator, Headless Display Adapter Supports up to 3840x2160@60Hz, 1080@120Hz DVI EDID Emulator (Single)

www.amazon.com

Looks much, MUCH sharper!

 

[abhi182]

Yes, HiDPI will “look like” 1920x1080 then. Or you can go for MSI or LG 5K2K display and then HiDPI will “look like” 2560x1080 but sharp (if you prefer UW screen aspect).

The answer is probably a little more nuanced than a simple 1:1 or 2:1 either/or for proper rendering.
I have been using a 24” 4K with an Intel MBP and now a M1 MBA for quite some time now.

As expected, the 2:1 native setup on the monitor (3840x2160) works very well and renders super sharp.
However as you can imagine, “looks like 1920x1080” renders too large for a 24” that sits 10-12”away

That’s why I have always used the more space setting in the display scaling with no noticeable loss of crispness/clarity in text rendering

What is interesting is that the more space setting shows up as UI looks like 2304X1296 / Resolution 4608 x2592 on system information

I am not sure how that works given the max res of the monitor is 3840x2160 - but I am not complaining as long as it works fine.

This probably also means that it should be possible to have hidpi on OPs monitor
It may be that the native / in-built rendering choices array does not have a set of values that suits it but it should be technically feasible to set it up manually

 

[AlphaCentauri]

The answer is probably a little more nuanced than a simple 1:1 or 2:1 either/or for proper rendering.
I have been using a 24” 4K with an Intel MBP and now a M1 MBA for quite some time now.

As I said, that was ideal situation. Non integer scaling is perfectly possible and many people are using it daily, however this puts a lot of strain on GPU (which matters for Macs with Intel integrated graphics) and is visually slightly less sharp. Perfectly acceptable, though.

What is interesting is that the more space setting shows up as UI looks like 2304X1296 / Resolution 4608 x2592 on system information

I am not sure how that works given the max res of the monitor is 3840x2160 - but I am not complaining as long as it works fine.

Screen is rendered at 4608x2592 by the GPU and then halved (HiDPI mode) to 2304x1296 and this is then displayed on 3840x2160 screen. As long as "looks like" resolution is less than actual resolution of the display, it can be displayed (assuming that OS X would deem it worthy and would include it on the list of available HiDPI resolutions).

Let's say that Mac OS X hypothetically would render 8000x5000 UI and made HiDPI out of it (looks like 4000x2500) - you wouldn't be able to display this on 3840x2160 screen, there is simply not enough pixels on 4K LCD panel to show the image.

 

[abhi182]

As I said, that was ideal situation. Non integer scaling is perfectly possible and many people are using it daily, however this puts a lot of strain on GPU (which matters for Macs with Intel integrated graphics) and is visually slightly less sharp. Perfectly acceptable, though.



Screen is rendered at 4608x2592 by the GPU and then halved (HiDPI mode) to 2304x1296 and this is then displayed on 3840x2160 screen. As long as "looks like" resolution is less than actual resolution of the display, it can be displayed (assuming that OS X would deem it worthy and would include it on the list of available HiDPI resolutions).

Let's say that Mac OS X hypothetically would render 8000x5000 UI and made HiDPI out of it (looks like 4000x2500) - you wouldn't be able to display this on 3840x2160 screen, there is simply not enough pixels on 4K LCD panel to show the image.

Ah, that makes sense.
I hadn't realised that it puts extra strain on the GPU and very likely the reason why my Intel mbp used to get so hot with external display.

Curiosly though, it does not seem to be taxing the M1 MBA..
Maybe it's just that there is enough grunt in there for it not to matter much.
I suppose running a test like geekbench metal to see the scores with internal only/ external at integer scaling/ external at non integer scaling to see what variance occurs.

Will post what I find.

 

[abhi182]

Oh well - The results are rather unusual

I tested 4 scenarios in total

Native - Internal only/ External in extended display mode

Scaled (more space) - Internal only/ External in extended display mode

3 of the 4 yielded scores that have statistically insignificant differences.
The only scenario which seems to have yielded a somewhat lower score is with the Internal monitor running on native resolution - which I would have expected to yield the highest score.
Weird !

 

[Thebnt]

Just in case anyone was looking for a headless M1 Mac Mini solution for HiDPI via remote desktop (knowing that you can't workaround it with SwitchResX, e.g.), I found that this "dummy" dongle works great on the M1.

BUYMINERS.CA 4K HDMI Dummy Plug - Virtual Monitor Display Emulator, Headless Display Adapter Supports up to 3840x2160@60Hz, 1080@120Hz DVI EDID Emulator (Single)

BUYMINERS.CA 4K HDMI Dummy Plug - Virtual Monitor Display Emulator, Headless Display Adapter Supports up to 3840x2160@60Hz, 1080@120Hz DVI EDID Emulator (Single)

www.amazon.com

Looks much, MUCH sharper!

Hey by using this device you can get 2160p at HiDPI? I.e. looks like 1080p??

 

[decipherkl]

Just received my Dell P3222QE today which is a 4K monitor. I am able to set up HiDPI with SwitchResX @3008x1692 60Hz. This monitor is connected to the Mac Mini M1. With HiDPI text definitely looks a lot sharper.