120% or 150% Scaling (Macbook Pro M3 | HiDPI)

[focusnetwork]

Hello,

I have two monitors attached:

• Dell U4025QW (WUHD 5120 x 2160)
• LG DualUp (SDQHD 2560 x 2880)

I am really struggling with the scaling on Mac OS (Macbook Pro M3).

There was a "120%" scaling option on BetterDisplay for the Dell, which has now disappeared (but this worked quite well).

Now I am only given the option of 100% or 200%.

120% or 150% would be preferable. How can I configure this?

On the LG, no percentage is shown and it is currently set to 1280x1440, which is confusing as this seems to be 50% of the actual resolution.

Bit confused. Any guidance to get these setup so things aren't too big or too small?

Much appreciated.

[waydabber]

How is the Dell display connected?

The LG DusalUp probably defaults to 1280x1440 HiDPI (which is a logical resolution, each logical pixel contains 2x2 actual pixels, so the actual video memory - framebuffer - resolution should be 2560x2880 which should be the same as the panel resolution).

[focusnetwork]

I am happy with the resolution of the LG.

The Dell is connected via Thunderbolt but everything is a bit too big. There was a 120% setting but this had disappeared. How can I configure this manually as well as 150%?

Thanks for your help!

[waydabber]

If the Dell display is natively connected, follow this to enable additional resolution options: https://github.com/waydabber/BetterDisplay/wiki/Fully-scalable-HiDPI-desktop

[focusnetwork]

Thanks @waydabber. I already have these options active, but I am only given the option of 100% or 200% on the scaling slider for this monitor (in HiDPI mode).

A few days ago 120% was visible, but that has disappeared.

I have added 2 "custom scaled resolutions" to try and match 120% and 150% but it says these are only supported in LoDPI and this affects the resolution.

Any suggestions on how I can set 120% and/or 150% in HiDPI mode?

Thanks in advance for your help.

[waydabber]

I am not sure, if only 100% and 200% is active then something is definetly wrong. Can you make some screenshots of what you see under the display's settings and the display mode menu in the app?

[focusnetwork]

@waydabber please see attached

[waydabber]

Oh, I think you are bumping into a max resolution limit of the GPU. You can check this under the display's Display Information... > Capabilities under the app Settings > Displays.

Looks like this:

This might happen if you use the HDMI port on some systems.

[focusnetwork]

@waydabber that seems to be the issue:

This display is connected via Thunderbolt, but the other one (LG) is on HDMI (via a hub). Is it worth trying some different connection configurations?

[waydabber]

Yes, by all means. Which chip does the Mac have? If it's the entry level one, then your options might be rather limited as its external display options (even in clamshell mode with the built-in screen's framebuffer repurposed to an external display) are rather resolution-constrained I am afraid.

[focusnetwork]

@waydabber I'm using the Macbook Pro M3 "base" model (i.e. not Max/Ultra).

I've made progress now by plugging the LG in with a HDMI to USB3 cable, which has given me back the 120% option on the Dell:

You mentioned HDMI could be holding things back. Could I expect any better performance using a Displayport to USB3 cable on the LG?

Ideally I want to try to get the Dell monitor up to 130% or 140%.

Thanks so much for your help.

[waydabber]

No, 3072px HiDPI (6K) is the max for entry level Apple Silicon Macs (you need Pro to get 3840px) for the primary external display output (secondary has a limit of 2560px HiDPI - 5K).

[kitch]

Not sure what on earth "3072, 3840 pixels HiDPI (6144, 7680 pixels LoDPI)" is supposed to mean but the end result is my macbook air can only drive my 5k2k at 3072x1296 HiDPI but my macbook pro can do up to 3840x1620