Dual USB-C displays

[Dentifrice]

Hi,

I read there are some limitations with dual displays on the M1 mac mini.

My current setup is 2 USB-C displays (4k) connected to a thunderbolt 4 hub. And of course, A single TB4 cable from the hub to my macbook.

Can this setup work or I really need the 2nd display to be directly connected to the mac mini with an HDMI cable?

Thanks

 

[russell_314]

Hi,

I read there are some limitations with dual displays on the M1 mac mini.

My current setup is 2 USB-C displays (4k) connected to a thunderbolt 4 hub. And of course, A single TB4 cable from the hub to my macbook.

Can this setup work or I really need the 2nd display to be directly connected to the mac mini with an HDMI cable?

Thanks

Normally you would connect one display to HDMI and the other to the thunderbolt connection. The Intel Mac mini supported multiple USB-C displays but not the M1.

I found this article talking about a way to use two USB-C displays. It might not be exactly what you're looking for though.

How to Run 2 Displays From an M1 Mac Mini – The Sweet Setup

Editor’s Note: The LG 4k monitors used for this article are model number 22MD4KA. Some readers have reported that the newer model (24MD4KB) does not work with the mentioned adapter because it requires Thunderbolt 3 instead of USB-C. The Siig adapter mentioned here will ONLY work with a USB-C...

thesweetsetup.com

 

[pshufd]

One thing that I noticed is that the HDMI monitor supports only up to 4k and the limitation here is the resolutions that you can get with a 4k monitor compared to the USB-C monitor. It was driving me nuts as to why there is this limitation but it's apparently due to the OS in terms of upscaling and then downscaling. My 2021 M1 Pro MacBook Pro does not have this limitation with 2 external monitors.

If you want the best external monitor support, get a Mac with the Max chip (2021 MacBook Pro or Mac Studio).

 

[EugW]

One thing that I noticed is that the HDMI monitor supports only up to 4k and the limitation here is the resolutions that you can get with a 4k monitor compared to the USB-C monitor. It was driving me nuts as to why there is this limitation but it's apparently due to the OS in terms of upscaling and then downscaling. My 2021 M1 Pro MacBook Pro does not have this limitation with 2 external monitors.

If you want the best external monitor support, get a Mac with the Max chip (2021 MacBook Pro or Mac Studio).

What resolutions are you missing? Which monitor?

P.S. My 4K+ 3840x2560 monitor can be run at full resolution over HDMI 2.0 with an M1 Mac mini, despite having 19% more pixels than 4K, but only at 50 Hz. To my pleasant surprise though, 50 Hz is fine. (30 Hz is not fine, but 50 Hz is fine.) My preferred 2304x1536 scaled resolution is supported over HDMI, but I know you prefer higher resolutions.

P.P.S. Another HDMI limitation specifically on Macs, is that Apple blocks DDC/CI through its HDMI port. So, you can't control brightness through the keyboard with an app like MonitorControl if you're using HDMI. You have to use the monitor's own brightness controls. Not the end of the world, but an annoyance nonetheless.

 

[pshufd]

What resolutions are you missing? Which monitor?

3,360 x 1,890 and 3,008 x 1,692. The resolution switchers can give you those but they turn out fuzzy.

 

[EugW]

3,360 x 1,890 and 3,008 x 1,692. The resolution switchers can give you those but they turn out fuzzy.

Interesting. I can confirm this with my monitor as well. 3008x2005 is there for USB-C, but it is missing over HDMI. However, I use 2304x1536 and it's supported on both, and I personally wouldn't even consider running anything beyond 2560x1707 (also supported on both).

Is it possible to get 2304x1296 hiDPI with the resolution switcher applications on the 5K Apple Studio Display? Because it's not offered by default on my 5K iMac natively.

USB-C:

HDMI:

 

[pshufd]

Interesting. I can confirm this with my monitor as well. 3008x2005 is there for USB-C, but it is missing over HDMI. However, I use 2304x1536 and it's supported on both, and I personally wouldn't even consider running anything beyond 2560x1707 (also supported on both).

Is it possible to get 2304x1296 hiDPI with the resolution switcher applications on the 5K Apple Studio Display? Because it's not offered by default on my 5K iMac natively.

USB-C:

View attachment 2134239

HDMI:

View attachment 2134240

I do not have an ASD and I'd think that the ASD would be able to give you more given that it's more of a computer than a monitor. I personally don't need a 5k monitor after having used one for a year. It is nice to use but there's no practical benefit (in terms of getting work done) for me. You could always try Show all resolutions and it may give you more but I found that those additional resolutions were fuzzy.

My experience on resolutions supported is that you have to find someone with the hardware that you're interested in and get them to try it on their hardware and give you the results. There is no magic matrix of hardware to hardware and what works. This is the frustrating aspect of monitors and Macs that a lot of people go through. There are even a lot of people that buy an M1 Air and don't realize that it only supports one external monitor as they expected more than one supported because it was on their Intel MacBook Air.

 

[EugW]

I do not have an ASD and I'd think that the ASD would be able to give you more given that it's more of a computer than a monitor.

Well, 2304x1296 isn't offered on my 5K iMac, and it is even more a computer than the Apple Studio Display.

I haven't tried installing SwitchResX though.

EDIT:

I just installed SwitchResX.

SwitchResX supports 2304x1296 HiDPI mode on my 5K iMac, but it doesn't get added as a macOS supported resolution. It's only switchable within the application itself. I guess that's the way this application works, assuming I'm using it correctly.

I'd be a little less than enthused to have to run SwitchResX all the time, since in the past it's borked my OS.

 

[pshufd]

Well, 2304x1296 isn't offered on my 5K iMac, and it is even more a computer than the Apple Studio Display.

I haven't tried installing SwitchResX though.

EDIT:

I just installed SwitchResX.

SwitchResX supports 2304x1296 HiDPI mode on my 5K iMac, but it doesn't get added as a macOS supported resolution. It's only switchable within the application itself. I guess that's the way this application works, assuming I'm using it correctly.

I'd be a little less than enthused to have to run SwitchResX all the time, since in the past it's borked my OS.

It may be due to some funny multiple of something. I have used EasyRes but I prefer not to use it as I have to remember to turn it on and off. I don't think that I'd leave it on all the time. I do run 2,560 x 1,600 on my laptops from time to time but I mainly use it at the default resolution most of the time.