Works on Big Sur M1 for HiDPI Displays

[coolaj86]

Confirmed that this works on Big Sur as well. Woohoo!

1. Option ⌥ click to open the BetterDummy app (to ignore the unsigned warning)
2. Option ⌥ click-n-drag the Dummy onto the Thunderbolt (to mirror 2 of 3 displays)
   
3. Select "Optimize for Dummy 16:9" and set the resolution to the target resolution (i.e. 1600x900 on the Dummy if you want to put a real 2560x1440 display into HiDPI/Retina mode)
   
4. Verify that the mirrored display is scaled to the BetterDummy display
   

Re: usr-sse2/RDM#26 (comment)

[waydabber]

I'll convert this into a discussion so others might know! Thanks for the info!

[coolaj86]

@waydabber The v1.0.2 release seems to have removed support for BigSur. v1.0.0 still had it.

[waydabber]

Hi @coolaj86 - what do you mean? The deployment target is still 11.0 so the app should technically be compatible with Big Sur - maybe I introduced some change that breaks compatibility? Can you describe how the issue manifests? Thank you?

(btw I think it is best to upgrade to Monterey as Apple did some stuff that fixes some of the issues for M1's notoriously buggy external display support in Big Sur - of course there are outstanding problems still).

[coolaj86]

Doh! I should have been clear on that one.

I've already upgraded (seeing that Monterey is mostly minor improvements and not a vast overhaul) but the issue was that the icon had a white circle + strike on it - like this 🚫, but white - the one that is used to mean "app not compatible with this version".

I think that's typical when some library or API is used that only exists in the newest version.

[waydabber]

Ahh I see. XCode should complain if this is the case during compile, but maybe something went wrong. I can't try it out now as I don't have a Big Sur mac, but thanks for the info and hopefully other Big Sur users will chime in if there is a problem.

[TGNYC]

The app opens on my Big Sur M1, but I seem to run into a problem where if I choose "Best for Dummy 16:9" in my external monitor settings, the Dummy Display resolution drops from the selected "2560 x 1440" to the default "1280 x 720". I'm not sure if this is a problem specific to Big Sur or just my specific case.

[JammingBen]

Happens to me as well on Big Sur. The fake display always defaults back to "1280 x 720".

[ricfwolff]

Happens the same to me on Big Sur. On step 4, when I try to change it to "Best for Dummy 16:9" in the external monitor, it'll revert Dummy back to 1280 x 720.

Have you found a way (@JammingBen , @TGNYC)?
Or maybe it's already working correctly and I'm just not seeing it? I've been using it for some time now. I don't know if I got used to or if it's fixed. (@coolaj86)

[ricfwolff]

I have now set both windows to "Scaled 2560 x 1440" and it feels better. Not sure if it worked. 🤦