Dummy mirroring + scaling on Intel - black bars + no HiDPI resolution?

[vincentcox]

Hello there,

Very promising project!!

Unfortunately, it appears that achieving scaled 2560×1080 (HDPi) on a 3440x1440 Display is causing some issues.

I tried the steps but somehow it is showing it boxed:

(content of the screen is blurred)

I tried both via usb c<->displayPort (100 Hz) as hdmi<->hdmi (60 Hz), to rule out that it's a high refresh rate issue because the readme is stating that high refresh rate displays are not supported.

[waydabber]

This should not be a high refresh rate issue. Can you please describe the setup (what Mac model are you using?) and could you send me the screenshots from System Preferences/Displays so I can review the display configuration? Thank you!

[vincentcox]

Is this information sufficient?

I can provide more information if needed!

[waydabber]

Hmm. A dummy does not seem to be present based on your screenshots.

[vincentcox]

Hello there,

I think you are looking after this?

[waydabber]

Yes. I see that you use the latest beta. What if you disable "Low resolution mode"?

Is the Dummy properly mirrored to the Acer display with the Dummy being the Mirror Main?

[vincentcox]

For some reason if I click "Low resolution mode" :

The icon gets filled in, but returns to the original state (as in the screenshot).

So I don't know if I disabled it completely, because it's still a check icon.

About the dummy being mirrored:

Should I try the non beta version?

[waydabber]

Hmm. Mirroring seems ok. If you press OPTION while clicking on "Scaled", do you see other resolutions (HiDPI and low resolution ones)? Can you change the resolution with that? Also you can try the stable version which has a standard menu based resolution selector. The 1.0.11 beta is a work in progress.

Uhh, I see that you have the Dummy itself in the association list (which is strange, that should not happen).

I test and develop the app on M1 under Monterey, so things might be quite different on Intel/Big Sur with a Radeon chip. It is interesting that mirroring seems to result in a letterboxed image on this config, I actually never seen something like that.

[vincentcox]

Hey there,

If you press OPTION while clicking on "Scaled", do you see other resolutions (HiDPI and low resolution ones)?

I had to do that to get to 2560×1080

Also you can try the stable version which has a standard menu based resolution selector.

With the stable it's the same issue, I just checked that

I test and develop the app on M1 under Monterey

Well, I can try to upgrade to Monterey. Normally I wait for an .1 version (so 12.1) because homebrew tools and versions of let's say PHP etc are not always fully working. But the 12.1 version is already in beta as far I can believe the internet.

Does your gut-feeling say it is because of the graphic card or the operating system (Monterey vs Big Sur)?

[waydabber]

I am not sure, my gut feeling is that this is more of an Intel+Radeon issue. I tried the app on Intel/Big Sur with an UHD630 and that seemed to work fine, also on M1. Unfortunately I don't have a comparable hardware to try.

Maybe others can chime in with similar hardware? I'll convert this to a discussion so others may participate.

[waydabber]

Also you could try SwitchResX to create custom HiDPI resolutions as that should work on Intel machines.

[vincentcox]

I've updated to Monterey, same problem unfortunately

[waydabber]

just to make sure can you show the screen config under System Report -> Graphics/Displays?

[waydabber]

(System Report is found under Apple Menu / About This Mac).

An other similar report from an other MacBook Pro but with Intel Iris:

#137

[vincentcox]

Hey there,

Here are the screenshots:

As told in the other thread, the dummy is indeed not showing in the overview.

Also I have the AMD card where the screen is connected to, the other thread has it connected to internal graphics (Intel).

[waydabber]

Yes. It seems Intel and M1 works differently in this regard. On M1 things look like this:

I'll try to experiment with an Intel mac to understand better how this works (unfortunately I sold all my Intel minis). I'll note the fact in the readme that on Intel things might not work that well - but for Intel there is alternative anyway, afaik RDM has a build that allows for changing resolutions and also there is SwitchResX (which is a great tool, I used that all the time on my Intel macs in the past).

[waydabber]

Let's move the discussion from #137 to here

@chonepieceyb: Question: if you enable Settings / Show low resolution in the app, then basically there is no difference between the HiDPI resolutions found in the menu and the Low resolution options (which should follow the HiDPI options if you scroll down)?

[vincentcox]

@waydabber, I have an iMac besides this macbook. Also Intel and AMD card. If you want I can create a guest account and install teamviewer on it so you have an intel dev environment. (Details should be discussed via a private channel)

[waydabber]

Hi @vincentcox thanks for the offer! :) I'll be able to test this on an Intel mac soon (although it is running Big Sur at the moment), that's more optimal since I can see the output of the display as it is (probably I would not see how things are really rendered through teamviewer). But if this can't be arranged, I'll let you know! Meanwhile I added this issue to the list of known issues as now at least two Intel users mentioned this as a problem.

[krackramadub]

@vincentcox @waydabber
Hi. I faced the same problem on MBA m1. For me helped me to crank the external monitor 180 degrees and return it back (System preference -> Monitors -> External monitor -> Rotate to 180deg -> Wait -> Return). Try it.

[leandro-tavares]

Hi, here I am using this option to work: rotate 180 degrees and return.
That's what has worked, but this (staying with the black border) has been happening all the time.

[vincentcox]

@waydabber, I was also wondering why I can't get both resolution in one dummy:

• 3440x1440
• 2560x1080
  Both are 21:9 ultrawide resolutions. I think if I can use both resolutions in one dummy I can make it work. I managed to get the boxed-issue fixed somehow, but if I can get those 2 resolutions in one dummy I can make it work.

edit: I tried switchresX to do that:

But that's not working.

[waydabber]

Hi @vincentcox - the two aspect ratios do not match perfectly (2.39:1 vs 2.37:1) that's why you can't use it with the same dummy.