Fundamental Screen Resolution Issues with macOS 11 (Big Sur) on Apple Silicon - Apple needs to act on that

I am trying to run an LG Ultrawide 5k2k screen on a brand new Apple M1 MacMini (Apple Silicon). This basically works fine. The display gets recognized as what it is and 5120x2160px is used as native resolution. The issue is with UI scaling.

The highest scaling is native resolution on this display which is nearly unusable (way too small). The second step already uses the infamous 3008x12xx (don't remember the exact height now). While kind of usable the UI is very big already at that scale. The scaling factor is close to 0.6 already at this stage - every other scaling option is again bigger (comically big up to macOS asking if I really want to use the bigger ones when I click them).

RDM is a little tool that thankfully gives me a full range of available resolutions which Apple seems to want to protect me from but that doesn't really help. The 3008x12xx is the highest available HiDPI resolution that apple provides for whatever reason.

Now SwitchResX is a classical solution to all resolution problem for over a decade now (as Apple always sucked at resolution things in macOS). Unfortunately Apple seems to have locked down all custom resolution stuff for BigSur on Apple Silicon. I still need to test on my old iMac if this would be a solution but for the Apple Silicon mac it currently isn't. No custom resolution is possible.

Apple has removed all capabilities to customise any resolution or monitor setting. If Apple doesn't change this or provide again monitors customisation features in macOS, ten this is definitely gone.

To be clear: What still works is using tools like RDM to select any resolution that is basically there but not visible and selectable through the macOS Display Settings PrefPane. What won't work anymore is customizing the resolution used for your display. This was often needed when macOS wasn't able to detect the right resolution with your display or if you needed to use overscan. Also for custom HiDPI-Resolutions (UI Scaling) there seems to be no other way than a custom resolution.

I'm thankful for any tip on how to solve the issue or how to bring this to Apple's attention.

The display I'm using is a modern, Thunderbolt 3 display from Apple's display partner LG. It offers quite a good quality and works great from plugging in. Due to scaling it's not really great to work with and I'm probably going to send it back.

This cuts down the possible options for an external HiDPI monitor to very few of which one at least is insanely expensive and would cost more than 3 times the money than the spec'd out MacMini.
If this means, that on M1 Macs is not possible anymore to create Custom Resolutions (HiDPi) using SwitchResX, this should affect quite a lot of users. It seems that this tool was the only way to create your own HiDPi resolutions. On your monitor, you may want to use a horizontal resolution of at least 3200 points, which should be still plenty sharp and give you more space.

I also had an eye on the LG Ultrafine 5k2k, but with this change to M1 Macs / MacOS 11 (Arm), I would also think twice before accepting to work on a 3008 points horizontal resolution.

SwitchResX was always a workaround to create resolutions that do work great, but are not supported by MacOS by default. There should be at least an option in Monitor settings to create and use any point resolution that meets the aspect ratio of the monitor (and is smaller than the native resolution of the panel).

Unfortunately this is an area in MacOS, were we didn't see any improvements since the 2012 Retina MacbookPro, so don't get your hopes up that apple will solve this any time soon (if ever).
I wanted to add another finding: This is totally an Apple Silicon issue. Connecting the same display to my 5k iMac from 2017 just works fine. The offered scaled resolutions are totally fine and usable. So i assume it would be a bug in BigSur for M1.

Scaled resolutions offered on the intel Mac are:

1600x675
1048x864
2560x1080
3360x1417
3840x1620

All of the sound reasonable to me while the lower 2 basically only should work fine for visual impaired people - they leave very little screen estate. From the middle one on this seems fine to me, especially the two higher ones. The right most one would perfectly match the 27" iMacs screen next to it which is about the same height. Scaled resolution used there is 2880x1620.

This finding leaves some hope for me that the issue is really only a bug in Big Sur for M1 but we will probably not know for sure until Apple says a word on it or even fixes it.

Still not sure if I should send the display back or keep it - basically it really looks nice in term of design and image quality.

EDIT: I just checked back on the MacMini with the Display attached. Scalings are actually the same from low to medium which I had in mind differently. But the higher two differ by a lot. Those are

3008x1269
5120x2160

The last one is unscaled 5k which is definitely way too small to be usable. The first of the two is working but the 1269pt of height are definitely way too low for a normal usecase for this display. You can already see the huge step between the two compared to when the display is attached to the iMac.

EDIT: I forgot to name the display. It's an LG 34WK95U-W
I have this same issue.

When using an Apple Macbook Pro/Air M1 and directly connecting the LG 34WK95U-W I am unable to use resolutions higher than 3008x1269. This is in contrast with the 2020 Macbook Pro 13" that I use that provides higher resolutions up to 3840x1620.

The hardware is definitely not the issue here as the Macbook M1 range supports the total pixel output using the internal display and the Apple XDR Display. This configuration renders a total number of pixels of 7,056,000 + 20,358,144 = 27,414,144 total pixels. This is compared to the pixels rendered in the desired LG 5K2K resolution of HiDPI 3840x1620 (True Resolution: 7680x3240) of 24,883,200. So in terms of raw output, the hardware can do it, but there appear to be some issues with external displays in general.

A non-exhaustive list of issues currently presenting on the M1 are:
  1. Intermittent resolution changes in screen wake.

  2. Intermittent misdetection of Monitor resulting in incorrect resolution options (No HiDPI)

  3. Prolonged black screen during wake and boot during monitor detection.

  4. Fewer "More space" options when selecting Scaled Resolutions on displays greater than 4K.

Hope this adds detail to this issue.



Same issue with my 2k dell monitor and Apple Silicon MBP 13inch. I can barely see the words on my screen, and if I use 1080p, it becomes burry. I tried all old way I can find but all in vain. I just switched from a surface pro and barely believe that such simple function can not be supported in Mac OS, it is just somehow shocking.
I do not think that Apple has "removed" this feature – but they are using a different framework now to drive the displays on the M1 Macs (the same one used on the iPhones and iPads, actually). Since the feature to modify the resolution and HiDPI support *is* there, I believe it is only a matter to configure the proper files. Which ones, of course I do not know, let us hope that the developer of SwitchResX will find out which ones :-) I am an optimist.
Not sure how it will bear upon the precise issue being described in this post, but I did just get Apple to acknowledge a bug (which they have committed to fixing) with Apple Silicon driving displays at HiDPI resolutions. Details here.

Curious is this still outstanding or its fixed already?

The free app BetterDummy resolves the resolution issues on M1 Apple Silicon, with one major drawback:

You lose HDR support

Thankfully it's easy to toggle BetterDummy as needed, but that's the current situation. It's due to a limitation behind the scenes with the macOS Quartz virtual display mirroring.

I was able to configure dual Pro Display XDRs at 3840x2160 HiDPI on a 14" M1 Max.

What worked for me on my Mac Studio (Should be similar for other M1/M2 devices):

Boot your computer on Safe Mode. Now go to Displays under System Settings (Mac OS version below 13.0, it's System Preferences). Enable Scaled under Resolution and select Show all resolutions. You should now see many more HiDPI options. Choose the one you like. Afterwards, just restart your computer. That's it!

To anyone reading this in 2024 and later - as six_montahue wrote above, I was able to resolve the initial issue of this thread (forcing a 5K2K monitor to output additional intermediary resolutions without hidpi loss) through use of the tool, BetterDisplay (new version of Better Dummy).

Since this took about 1.5 hours of digging through random forums and Reddit threads, I created a short guide with screenshots to save time for anyone else who stumbles upon this thread. https://docs.google.com/document/d/1YcVmhAZuN-xP87NZ_LZogPI0c8ZsYCjP731z1aQf22k/edit?usp=sharing

Fundamental Screen Resolution Issues with macOS 11 (Big Sur) on Apple Silicon - Apple needs to act on that
 
 
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