Mac mini M1 and two 4K monitors scaled to 1440p, any performance issues?

[manhas]

I'm about to pull the trigger on ordering two 4K monitors (LG 27UN880) for a dual monitor setup with my Mac mini M1 16 GB. I would like to scale both 4K monitors to 1440p, would there be any performance issues when scaling two 4K monitors compared to one that seems to work fine on M1 from what I've read?

I sometimes work with large and layer heavy files in Photoshop and doing some editing in Lightroom. I don't want the UI to get sluggish when doing graphic heavy tasks with scaling mode turned on.

 

[opeter]

This is good a question... Let's not forget, the integrated GPU is using the system RAM for any graphical operations.

I am also interested in this, hope someone can answer.

 

[Fozziebear40]

I saw a thread on Reddit and here is one reply....

"Yes, I’m running two 4K monitors and 60hz on the M1 Mini and it has been a dream. Incredibly smooth, stable, and fast. I love it!"

Reddit thread....

 

[opeter]

Yes, but that thread on Reddit says, that he is running in native 4K and not scaled down.

That is a big difference, because in the first post the original poster is asking, if the computer is still smooth, when all the graphics needs to be constantly scaled down and redrawn every (mili)second.

 

[OSX15]

I can only comment on scaling to 1440P with one 4K monitor, this works flawlessly and doesn’t seem to affect performance one bit.

 

[manhas]

Perhaps I could assume that anyone using a 27 inch 4K is using scaling since native 4K have an almost unusable small UI. I haven't read any comments about performance issues when using two 4K monitors with the M1, so perhaps two monitors with scaling work just as good as a single one. But it would be reassuring to have it confirmed.

 

[manhas]

So I've now bought two LG 27UN880-B monitors and I've been using them for the past week. Performance wise it works okay, both are scaled to high resolution 1440p, I haven't noticed any sluggishness.

I'm more disappointed in how macOS and the m1 handles the different display ports. Not full color range over USB-C by default, the colors/contrast are washed out over HDMI unless I do extreme color calibration and no DCC for the HDMI display.

I've noticed that WindowServer occupies more memory in general now compared to before, but then again I had a single 1440p monitor compared to two 4k now.

 

[Dubadai]

So I've now bought two LG 27UN880-B monitors and I've been using them for the past week. Performance wise it works okay, both are scaled to high resolution 1440p, I haven't noticed and sluggishness.

I'm more disappointed in how macOS and the m1 handles the different display ports. Not full color range over USB-C by default, the colors/contrast are washed out over HDMI unless I do extreme color calibration and no DCC for the HDMI display.

I've noticed that WindowServer occupies more memory in general now compared to before, but then again I had a single 1440p monitor compared to two 4k now.

Could you post a picture of the screens side by side?

Is the difference in colors and contrast so bad that you’d not want to use dual monitors?

Since they didn’t update the M1 Mac Mini today I am inclined to just get the one that is available and run two monitors connected to it, but if there are issues with colors on the screens that’s of course an issue.

 

[3lmanana]

I have 27” 4K display scaled down to 1440p with M1 MBP13 16 GB.
It does affect performance a lot. I noticed that the UI is a lot laggier than my previous base MBP16. All UI animations have frame drops, preview for images is laggy as hell… I am a bit disappointed.

At job I have 32” 4k display scaled down to 3008xsomething and works much faster. This scqling factor on 27” display kills performance a lot.

 

[manhas]

Could you post a picture of the screens side by side?

Is the difference in colors and contrast so bad that you’d not want to use dual monitors?

Since they didn’t update the M1 Mac Mini today I am inclined to just get the one that is available and run two monitors connected to it, but if there are issues with colors on the screens that’s of course an issue.

Not sure if a picture would be of any help if it's for the colors.

After hours of adjusting screen colors and creating ICC profiles (without calibration tool) both monitors look basically the same and I don't notice any difference in color or contrast between them side by side. The colors also look similar to what the MacBook Pro produce when placed next to them. So it's good enough for me since I mainly use them for development and it's more important for me that the two monitors display the same colors and not necessarily the correct ones (within reasonably limits off course).

I might get a calibration tool just so that I know that the colors are correct and since calibrating the monitors equally without a calibration tool was barely manageable when they were so off to start with.