I have now tried the "BetterDummy" program and checked whether it can provide a solution for the missing HiDPI resolutions via DisplayLink.
The good news is: Yes, it is a woraround to get HiDPI representation via DisplayLink.
My configuration:
- MacBook Air M1 (clamshell mode, internal display not used)
- MacOS Monterey 12.0.1
- 2x LG HDR 4k monitor (used @ Looks like 2560 x 1440)
Monitor # 1: connected via USB-C to display port adapter (working HiDPI @ 2560 x 1440)
Monitor # 2: connected via Display-Link Dock "Kensington SD4780P" (no HiDPI out of the box)
The Workaround for HiDPI on Monitor #2:
1.
Install and start "BetterDummy" from
https://github.com/waydabber/BetterDummy/releases
2.
Create a dummy Display "16:9 (HD/4k/5k/6k)
3.
In the display properties set the "Dummy Display" to:
- extended display
- optimized for: Dummy 16:9
- Resolution: default for display
4.
Switch Resolution of Dummy to desired HiDPI resolution (eg. 2560 x 1440) using the BetterDummy Menu: "Manage dummies" --> "Set resolution"
5.
Set your Display-Link Display in the display properties to:
- mirror 16:9 dummy
- optimized for: Dummy 16:9
- Resolution: default for display
6.
Optional settings of BetterDummy:
--> Now you should have a 2560 x 1440 HiDPI @ 4k
My LG HDR 4k Monitor via DisplayLink is now running @ 3840x2160/60Hz showing 2560x1440 in a crystal clear picture.
This is not a straight forward solution, but now I have two external 4k monitors on my MacBook Air M1 that work with HiDPI to my fullest satisfaction.