Macbook M1 and HiDPI support on a 5120x2160 monitor?

[lewismoss]

I am using an M1 MacBook Air.

I have bought a Samsung Odyssey G75f 40 inch, which has resolution 5120x2160. I have messed around a little bit with BetterDisplay, and the best I've managed to get (that is lower than the native 5120x2160 - the text is too small with this res) is 3008x1269. Everything in between is 'low resolution' and looks terrible/fuzzy.

Is there any solution at all to this? Can I get a resolution between 3008x1269 and 5120x2160 and not have it look terrible/fuzzy?

On the rabbit hole on the way to this forum, I seemed to find that the M1 has some sort of limit of 3072 pixels wide, above which you cant scale properly? Is this correct? Is there no workaround whatsoever for this?

[waydabber]

You can enable 8K+ resolution under Settings/Displays/Overview/Additional settings…, create a virtual screen with the appropriate aspect ratio and then mirror the virtual screen it to the display. You can then change the HiDPI resolution of the virtual screen to your liking. This might serve as a workaround.

[lewismoss]

Thanks - this worked! Now I can get any resolution between 3008x1269 and 5120x2160 and it looks great!
Just to ask further: it does look great to my eyes, is there any loss in ppi/quality or anything like that with this method? Also, probably a big ask but can I set the refresh rate in this mirroring mode? I do seem to have lost settings to change it for the virtual display and it looks to be stuck on 60hz but I have a 180hz display (I never managed to get over 120hz natively anyway)

[waydabber]

You can try adding custom refresh rates to virtual screen (they are 60Hz by default), but it may not work as expected.

[fresh2dev]

@lewismoss, could you share more specifics on how you configured BetterDisplay to make your monitor look better on an M-series Mac? I recently bought the same monitor (Samsung G75F 40"), and I can't achieve anything that looks great; barely good is the best I've got... =/

[0r3h]

@lewismoss can I ask you to report on performance you are getting with M1 Air and Virtual screen?

Since ~2022 I was able to run M1 Air with Dell U4021QW at 4096x1728 HiDPI using BetterDisplay Virutal screen and it was running great.

However for the last few months I've been experiencing some issues with it and especially now with Tahoe it became unusable. The problem is especially noticable when running electron apps (VSCode, Slack, ...), playing videos in a browser, ... Some graphical artifacts can be seen when moving electron windows around, system becomes laggy, eventually freezes.

Glitches might be related to some Color profile bug but I was unable to resolve it by playing around with the Color modes. I tried clean installing MacOS and played around with various stuff but sadly no luck.

I'm not sure if it is a HW issue, OS issue, BetterDisplay issue or some other thing. Currenlty after about three weeks of on/off fiddling with it I was not able to pin it down and kinda just became used to running it at 5120x2160. Would still love to have 4096x1728 or 3840x1620 back.

[0r3h]

I'm talking about GPU usage. Although I see some elevated CPU usage when BetterDisplay menu bar GUI (see Core 5 during #1 scenario).

1. BetterDisplay menu bar GUI open
2. BetterDisplay full GUI open and in focus
3. BetterDisplay full GUI open and not in focus

I tried the same with VirtualScreen disabled:

Here are also results for GPU usage with Virtual screen enabled from sudo powermetrics --samplers gpu_power -i 1000:
1.

GPU HW active frequency: 740 MHz
GPU HW active residency:  67.25% (396 MHz: 6.7% 528 MHz:  14% 720 MHz:  23% 924 MHz:  16% 1128 MHz: 6.8% 1278 MHz: .21%)
GPU SW requested state: (P1 :  10% P2 :  25% P3 :  34% P4 :  22% P5 : 8.7% P6 : .33%)
GPU idle residency:  32.75%
GPU Power: 1200 mW

GPU HW active frequency: 844 MHz
GPU HW active residency:  25.17% (396 MHz: 5.7% 528 MHz: .59% 720 MHz: 5.3% 924 MHz: 5.3% 1128 MHz: 4.3% 1278 MHz: 4.0%)
GPU SW requested state: (P1 :  22% P2 : 4.3% P3 :  20% P4 :  21% P5 :  18% P6 :  15%)
GPU idle residency:  74.83%
GPU Power: 724 mW

GPU HW active frequency: 396 MHz
GPU HW active residency:   3.69% (396 MHz: 3.7% 528 MHz:   0% 720 MHz:   0% 924 MHz:   0% 1128 MHz:   0% 1278 MHz:   0%)
GPU SW requested state: (P1 : 100% P2 :   0% P3 :   0% P4 :   0% P5 :   0% P6 :   0%)
GPU idle residency:  96.31%
GPU Power: 10 mW

Idle state for reference:

GPU HW active frequency: 396 MHz
GPU HW active residency:   2.67% (396 MHz: 2.7% 528 MHz:   0% 720 MHz:   0% 924 MHz:   0% 1128 MHz:   0% 1278 MHz:   0%)
GPU SW requested state: (P1 : 100% P2 :   0% P3 :   0% P4 :   0% P5 :   0% P6 :   0%)
GPU idle residency:  97.33%
GPU Power: 6 mW

[waydabber]

Oh, GPU. Not sure why, the UI uses Glass heavily on Tahoe, but I see only 0-1% GPU usage at most (although I am using an M3 Max). For sure M1 struggles a bit with Glass (still nothing compared to what happens on Intel Macs with iGPUs… ;)), it is evident from some of the effects scaled down with large glass surfaces (did some tests), but I did not see any serious slowdown issue even on an the most entry level M1 mini I used while testing.

[0r3h]

Oh, I might have found something: I previously enabled "Reduce transparency" in MacOS Acessiblity settings in effort to hopefully reduce the GPU load. It seems that this might not play well with BetterDisplay GUI. After I disabled Reduce transparency, GPU load dropped when BetterDisplay GUI is in focus.

1. BetterDisplay GUI in focus, Reduce transparency enabled
2. BetterDisplay GUI in focus, Reduce transparency disabled

Thank you for your help or at least nudging me to try stuff out again. It seems that for now my setup is back to how it used to be and I don't have to struggle with tiny text on full resolution. From my side this issue is resolved, if you need any help debugging anything I'll be happy to help though. I was a freeloather before, you made me get the Pro license with your responsivnes. Thank you for your great work!

[waydabber]

Hmm. Weird. Reducing transparency should not make things slower… I think. The app uses native Glass effects provided by macOS, so it seems like there might be a bug in Tahoe that makes reducing transparency even heavier? Good to know, thank you for this info!

Does turning off reduce transparency help with Electron apps as well?

[0r3h]

I did not notice any difference with Electron apps.