M1 Macs not enabling Retina mode with certain monitors, developer says

Posted:
in macOS
Some M1 Mac owners are complaining about blurry text and lower-than-expected resolutions when using some third-party monitors, and one app developer has discovered why.

Certain third-party monitors may not perform well when used with an M1 Mac.
Certain third-party monitors may not perform well when used with an M1 Mac.


Complaints about resolution and blur problems when plugging in a sub-4K monitor into an M1 Mac have surfaced on support boards since the launch of Apple Silicon. App developer Istvan Toth has investigated the issue and developed a fix.

Toth told The Register that the problem centers on the fact that macOS isn't enabling its Retina-based high-pixel density mode (HiDPI) when plugging into to certain third-party monitors. Additionally, M1 Macs may offer lower resolutions than what a third-party monitor is capable of.

"It all comes down to font and widget scaling, and resolution independence. What Apple calls HiDPI mode is just the OS recognizing the plugged display operates at a super-high pixel count and scaling the desktop and user interface accordingly," Toth said.

Toth theorized that the issue could be due to the fact that Arm-based Mac devices use the same graphics driver code as iOS or iPadOS. Those devices don't need to support multiple displays, or displays that don't fall within a specific range.

"On some displays, like those sub-4K displays with 1080p or 1440p resolutions, Apple Silicon Macs do not allow high-resolution display modes, namely HiDPI, and does not do scaling well," he said. "This results in a low-res desktop experience locking the user with too small or too big fonts and GUI, and there is no way to change that."

On some displays, such as those in the 1080p range, the issue isn't as noticeable. But users who have larger or wider QHD displays might see fonts that are too small and blurry widgets and graphics.

Toth said the issue is software-based, and could be fixable in a macOS update. In the meantime, he has created an app that could mitigate the problem.

BetterDummy, Toth's app, basically creates a virtual display in software and mirrors it to a real display. That coaxes macOS into enabling the proper display mechanisms. BetterDummy is MIT-licensed and open-source.

AppleInsider has been trying to discuss monitors and Apple Silicon Macs with Apple since original release, but we have yet to have any responses to our queries.

Read on AppleInsider

Comments

  • Reply 1 of 6
    I just finished exhaustively testing everything from some old 1080p monitors up to my 4k and 5k norming every day monitors, culminating in my Samsung Oddysey G9 monitor (49" UltraWide 5120x1440) and can't say I've seen the problem except when using "older" cables from a couple years ago. For example, initially when connecting my 16" M1 Max MBP to the monitors, using HDMI cables, yes, there were definitely fewer resolution options and fewer refresh rate options. When I purchased a $30 USB-C to DisplayPort cable off of Amazon, suddenly I saw and had access to every resolution my PC testing workstation saw and I was able to run that monster 49" screen at max resolution, 120Hz without a hitch. I won't claim to have an amazing database to reference for this, but I can say with 100% certainty that ensuring you are buying new, HIGH QUALITY, cables, and using either direct USB-C, Thunderbolt, or DisplayPort connections on monitors will always give you the same and often far greater options and quality. :-)

    Here's a link to a little graphic I created over a Flight Sim forum a couple weeks back where I was starting to help people understand the performance of the M1 and M1 Max and monitor resolutions...etc https://forums.x-plane.org/index.php?/forums/topic/256791-chart-screen-resolution-and-fov-v1/
    muthuk_vanalingamFileMakerFellermacplusplus
  • Reply 2 of 6
    When I plug my Apple Thunderbolt Display (2560x1440p) into my M1 Mini it looks and works as expected. Same as when I plug it into my iMac Retina.

    That said, I don’t use it that way now, I connect to it remotely instead (Jump Desktop) as I have multiple Macs. I undertand that using BetterDummy prevents the use of screen-sharing so would be no use for me. 
  • Reply 3 of 6
    brockgs said:
    I just finished exhaustively testing everything from some old 1080p monitors up to my 4k and 5k norming every day monitors, culminating in my Samsung Oddysey G9 monitor (49" UltraWide 5120x1440) and can't say I've seen the problem except when using "older" cables from a couple years ago. For example, initially when connecting my 16" M1 Max MBP to the monitors, using HDMI cables, yes, there were definitely fewer resolution options and fewer refresh rate options. When I purchased a $30 USB-C to DisplayPort cable off of Amazon, suddenly I saw and had access to every resolution my PC testing workstation saw and I was able to run that monster 49" screen at max resolution, 120Hz without a hitch. I won't claim to have an amazing database to reference for this, but I can say with 100% certainty that ensuring you are buying new, HIGH QUALITY, cables, and using either direct USB-C, Thunderbolt, or DisplayPort connections on monitors will always give you the same and often far greater options and quality. :-)

    Here's a link to a little graphic I created over a Flight Sim forum a couple weeks back where I was starting to help people understand the performance of the M1 and M1 Max and monitor resolutions...etc https://forums.x-plane.org/index.php?/forums/topic/256791-chart-screen-resolution-and-fov-v1/
    I have seen the same with a 2021 MBP 16" M1Pro. I had huge problems connecting to a relatively new mid-range 1080p monitor. The built-in HDMI did not work, 3 separate USB-C/Thunderbolt to HDMI converters did not work. In the end changing the HDMI cable fixed the problem.
    williamlondon
  • Reply 4 of 6
    brockgs said:
    I just finished exhaustively testing everything from some old 1080p monitors up to my 4k and 5k norming every day monitors, culminating in my Samsung Oddysey G9 monitor (49" UltraWide 5120x1440) and can't say I've seen the problem except when using "older" cables from a couple years ago. For example, initially when connecting my 16" M1 Max MBP to the monitors, using HDMI cables, yes, there were definitely fewer resolution options and fewer refresh rate options. When I purchased a $30 USB-C to DisplayPort cable off of Amazon, suddenly I saw and had access to every resolution my PC testing workstation saw and I was able to run that monster 49" screen at max resolution, 120Hz without a hitch. I won't claim to have an amazing database to reference for this, but I can say with 100% certainty that ensuring you are buying new, HIGH QUALITY, cables, and using either direct USB-C, Thunderbolt, or DisplayPort connections on monitors will always give you the same and often far greater options and quality. :-)

    Here's a link to a little graphic I created over a Flight Sim forum a couple weeks back where I was starting to help people understand the performance of the M1 and M1 Max and monitor resolutions...etc https://forums.x-plane.org/index.php?/forums/topic/256791-chart-screen-resolution-and-fov-v1/
    I had to register just to say that I have the same Samsung Odyssey G9 49" 1440x5120 QHD monitor & a BenQ 4k photography monitor and since the Monterey 12.0.1 update my M1 MacBook Air will no longer output anything higher than 1920x1080. The M1 Air worked perfectly for 6 months on Sierra OS, using both high quality usb c to DP and usb c to usb c cables. It also scaled perfectly with el cheapo HDMI to HDMI via a usb c adapter. It all borked-up when apple pushed out Monterey.  I would suggest that this problem is not cable related, rather driver related. Either way, it's a huge PITA for everyone. I've been talking with Apple support for a week now and the only 'solution' they can offer is to roll back the OS!
    williamlondon
  • Reply 5 of 6
    brockgs said:
    I just finished exhaustively testing everything from some old 1080p monitors up to my 4k and 5k norming every day monitors, culminating in my Samsung Oddysey G9 monitor (49" UltraWide 5120x1440) and can't say I've seen the problem except when using "older" cables from a couple years ago. For example, initially when connecting my 16" M1 Max MBP to the monitors, using HDMI cables, yes, there were definitely fewer resolution options and fewer refresh rate options. When I purchased a $30 USB-C to DisplayPort cable off of Amazon, suddenly I saw and had access to every resolution my PC testing workstation saw and I was able to run that monster 49" screen at max resolution, 120Hz without a hitch. I won't claim to have an amazing database to reference for this, but I can say with 100% certainty that ensuring you are buying new, HIGH QUALITY, cables, and using either direct USB-C, Thunderbolt, or DisplayPort connections on monitors will always give you the same and often far greater options and quality. :-)

    Here's a link to a little graphic I created over a Flight Sim forum a couple weeks back where I was starting to help people understand the performance of the M1 and M1 Max and monitor resolutions...etc https://forums.x-plane.org/index.php?/forums/topic/256791-chart-screen-resolution-and-fov-v1/
    I don't think the issue the post is talking about would be too noticeable in Flight Sim, or videos, or games. It's more of a UI element scaling issue. So that's why text looks sharp or not sharp on some models. It's because the elements scale well or don't, or because some monitors have the right PPI and Screen Ratio so that macOS enables the HiDPI mode for those monitors. So while yes, cables might create other issues, the problem this article is talking about isn't necessarily a cable issue, but an OS software issue. 
  • Reply 6 of 6
    LG 40wp95c, 5120x2160@72 + Mac mini M1. The issue is there, extremely frustrating. I take the cord out of Mac mini M1, plug it into a MacBook Pro 16" 2019 Intel, no problem, all the Retina display resolutions show for the taking. This is the exact same monitor and cable, just a different Mac computer.
    muthuk_vanalingam
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