Help understanding HiDPI behavior

[ciaoben]

Hi,
I need help understanding a strange behaviour.
I have an external display QHD 27 inch, this one: https://aoc.com/it/products/monitors/q2778vqe

I have two macbook pro:

• macbook pro m1 pro 14"
• macbook pro 16" Intel 2019

On both the macs I installed BetterDisplay.
I attach both via DVI to Thunderbolt port, with the same cable.

If I attach the M1 pro macbook, I can use the full QHD resolution of the monitor: 2560 x 1440 AND enable HiDPI, and everything is perfect.

When I attach the macbook pro 16" intel, I can enable HiDPI on the same monitor only with a resolution of 1920x1200.

If I click on the max resolution I can't enable HiDPI with the 16" intel mac.
Can someone help me understanding why?

[waydabber]

Did you enable flexible scaling?

https://github.com/waydabber/BetterDisplay/wiki/Fully-scalable-HiDPI-desktop

[ciaoben]

I missed that, thanks.

I enable it but when I try to enable HiDPI it does not remain ON, here is the video:
https://github.com/waydabber/BetterDisplay/assets/4526061/c03e090d-1e88-4179-85ca-e07d743eddf1

Here are my settings:

[ciaoben]

Furthermore, now even when I disable the flexibile options I can't coming back to the old resolutions and HiDPI. I keep seeing all the resolutions like when the flexible option is ON...

[waydabber]

Do you see a non-HiDPI variant in the Display Mode? Click on Filter... and select the LoDPI tag and hit Apply for that and try a non-HiDPI resolution.

There is an issue with the main menu HiDPI toggle in v2.3.7 so it might not always work on some configs, not sure if this is the problem. This is fixed in v2.3.8, here is a download:

https://github.com/waydabber/BetterDisplay/releases/download/v2.0.0-pre-release/BetterDisplay-v2.3.8-b31277-pre.zip

Note: if you have a Mac with Intel iGPU, there is a bug in the Intel video driver so some modes just generally don't work. This is a macOS issue.

[waydabber]

To disable HiDPI resolutions on Intel in general, you can simply issue this command in Terminal and restart:

defaults write /Library/Preferences/com.apple.windowserver DisplayResolutionEnabled -bool NO

With custom system configuration enabled the app enables HiDPI resolutions and does not revert this as that is not considered by most.