Wrong dummy display resolution when connected via display link

[onreg]

MacBook:

1. MacBook Pro (13-inch, M1, 2020)
2. macOS version 12.4 (21F79)

Displays:

1. LG UltraGear 27GP850 27" 2560x1440px 165Hz, connected via displayport.
2. LG UltraGear 27GN850-B 27" 2560x1440px 144Hz, connected via displayport.

BetterDisplay:

1. Version 1.2.5c-bet Build 7617

Both displays are connected to my MacBook via Displaylink.

Then I create 2 dummy displays and set up mirroring.
Create New Dummy -> Create and configure for LG UltraGear (1) -> Connect and Set up Mirroring.
Create New Dummy -> Create and configure for LG UltraGear (2) -> Connect and Set up Mirroring.

After it, I am able to scale displays, but it seems to me that the resolution of the dummy display is not 2k. If I compare the dummy display vs the original display, the second one will have better quality. Is it the expected behaviour of using dummy displays with display link?

[waydabber]

Hmm. I think DisplayLink will not support screens beyond 60Hz (just seeing the high refresh rates there).

Well, the two displays should look the same if both dummies are set up the same way and both are mirrored to the display. The mirror will honor whatever the native resolution is reported by the target device so if you think it is not 2K then there might be something wrong there. You can check the native resolution by enabling these and checking out what is the reported native resolution for the display.

Also double check whether both dummies are currently configured as HiDPI (More Options/Low Resolution Mode is unchecked).

If mirroring does not work well, you can try streaming. For displaylink devices this tends to produce a better image, for whatever reason mirroring does not look right according to earlier tests of DisplayLink users - but I don't have a device like that myself so I cannot fully confirm that:

#173

[onreg]

Thank you. I switched mirroring to streaming and the image quality is improved (both dummy displays are set up to 1920x1080 60Hz).

[waydabber]

Thanks for the response!