HiDPI resolutions on M1 Mac - dual screen setup

[Tibi]

So you are totally RIGHT !!!

For the last 3 weeks I am using dual 27inch 4k at 1080 resolution and it was horrible ... now, I created 2 dummy displays and set resolution to 2560 x 1440 and the text is super sharp.

After creating the dummy's I set for my physical dual screen's to mirror the dummies and problem solved. !!!

Even the cursor moves much smoother !!!

Thank you !!

[tommiy]

Are you saying your not using DisplayLink at all?

[JanB]

Originally Posted by tommiy

Are you saying your not using DisplayLink at all?

No, the DisplayLink software is still needed. BetterDummy creates a virtual display with the needed geometry and supports HiDPI for various resolutions.

The HiDPI result of the virtual screen is mirrored to the DisplayLink display running @ 4k.

[Tibi]

Base idea is that with betterdummy it's a workaround.

What I observed, if you use 2 dummy screens and use a lot of MS Teams for online meetings, the fan of the MBP si starting ... I have a MBP M1 and it's the first time when I notice the fan starting so probably this solution puts more pressure on the CPU ...

Waiting for DisplayLink to fix their software so we would not need workarounds ...

[JanB]

Originally Posted by Tibi

I have a MBP M1 and it's the first time when I notice the fan starting so probably this solution puts more pressure on the CPU ...

I'm using a MacBook Air M1 with 16GB of RAM, and I haven't found DisplayLink or BetterDummy to require a noticeable amount of CPU power, at least in my typical workload.

Since the Macbook Air doesn't have a fan, I can't hear it, of course, but I took some measurements:

Idle without DisplayLink Screen connected
System: 7%, User 2-3%

Idle with DisplayLink Screen connected
System: 7%, User 3-4%

4K Video fullscreen on USB-C connected Screen
System: 12%, User 10%

4K Video fullscreen on DisplayLink @4k
System: 12%, User 17%

4K Video fullscreen on DisplayLink @4k + BetterDummy Screen
System: 12%, User 17%

*Idle means Word, Excel, Browser, Mail etc. open, but not used


It seems, that DisplayLink (and BetterDummy) are consuming of course some CPU resources, but I see no difference using the Dummy screens or not. From my point of view (unsing one 4k screen via DisplayLink) the amount of CPU used for DisplayLink is ok.

MS Teams of course is not a very friendly application at MacOS, it always consumes lot of resources.

But I agree, that HiDPI should be integrated in the DisplayLink software.

[Taubi]

Hi,

I also have a 4K monitor (Dell U2720Q) and beside resolution issues you are mentioning, I noticed that USB ports on the monitor itself are not working if using D6000 dock.

Did USB´s work for you?

The only workaround I could find was - connecting additional cable to the dock --> USB-C to USB3.0 cable. So basically I used 2 cables, one for video (Display Port) and one for USB´s which is horrible but ok.

[JanB]

Originally Posted by Taubi

Hi,

I also have a 4K monitor (Dell U2720Q) and beside resolution issues you are mentioning, I noticed that USB ports on the monitor itself are not working if using D6000 dock.

Did USB´s work for you?

The only workaround I could find was - connecting additional cable to the dock --> USB-C to USB3.0 cable. So basically I used 2 cables, one for video (Display Port) and one for USB´s which is horrible but ok.

My LG display is connected by DisplayPort, and does not support USB. Therefore, I have no experience with USB on the monitor.