Dual Dell QHD with USB-C Monitor Setup with Mac Mini M1

No, unfortunately, one must be HDMI-connected:

From Mac mini (M1, 2020) - Technical specifications - Apple Support

Dell – Dell 27 USB-C Monitor - S2722DC

Dell – Dell S2722DC Monitor User’s Guide

This is a 2560x1440 pixel monitor with three video inputs: a USB-C (DisplayPort) input, and two HDMI inputs.

Because this monitor can take HDMI input, I believe that you could connect two to your M1 Mac mini.

The only way to do so would be

• To connect one of the S2722DC monitors to the HDMI port on your M1 Mac mini.
• To connect one of the S2722DC monitors to the USB-C port on your M1 Mac mini. The most obvious way of doing this connection would be USB-C to USB-C, although a USB-C to HDMI adapter could also work.

If you wanted to use the integrated USB hub on a HDMI-connected S2722DC monitor, you would need to run a separate USB-A to USB-C cable from one of the USB-A ports on your M1 Mac mini to the monitor's USB-C port.

There is a reason why I say USB-A: USB-A ports are incapable of carrying DisplayPort video, and so plugging a S2722DC into one of your Mini's USB-A ports will only result in the two trying to speak USB protocol. If you ran both a HDMI-to-HDMI cable and a USB-C to USB-C cable to the "HDMI-connected" S2722DC, with the idea of using the USB-C to USB-C cable only to connect the monitor's USB hub ports, the computer and monitor might think that you were trying to establish a second USB-C (DisplayPort) link (which a M1 Mini wouldn't support).

+1 No. The M1 Mac mini only supports one display from the TB/USB-C port and one from the HDMI port.

In addition to the M1 Mac mini Spec's that hcsitas posted, see > Connect a display to Mac mini - Apple Support

However, according to > https://www.dell.com/en-us/shop/dell-27-usb-c-monitor-s2722dc/apd/210-bbqs/monitors-monitor-accessories#techspecs_section those Dell displays also have HDMI input ports.

If you have your mind set on those Dell's...? What I would do, is connect one to the HDMI port and the other to one to a TB/USB-C ports using a USB-C to HDMI adapter. That way you should be able to match the Resolution of the displays.

The only problem that I'm concerned with about this setup, is the ability to select true WideScreen resolutions.

alain217 wrote:

Thanks for the short answer but, I still don't understand why both Usb c ports on the mac mini can't be used to run each of the monitor displays tho? strange

The base M1 chip supports a maximum of two displays – no matter what chassis it is in.

• In the M1 MacBook Airs, 13" M1 MacBook Pros, and 24" M1 4.5K Retina iMacs, one video output is hard-wired to the built-in display.
• In the M1 Mac mini, one video output is hard-wired to the HDMI port.

Thus the limit on all of these M1-based Macs of a single USB-C (DIsplayPort) or Thunderbolt display. You can use either USB-C / Thunderbolt port to plug in the display – but the fact that there are two ports does not do anything to increase the number of available video outputs.

The base M2 chip also has a two-display limit, but M2 Mac minis are more flexible about display arrangements. If you leave the HDMI port on a M2 Mac mini open, that Mini can drive two USB-C or Thunderbolt displays.

The M2 Pro Mac minis have a higher-end chip with more onboard display support, and can drive up to three displays (attached to one of their four USB-C / Thunderbolt ports, or to their HDMI ports).

I see that Dell says that the monitor has a refresh rate of 75 Hz.

Looking in the manual, it indicates that for HDMI and for USB-C, the monitor has preset 2560x1440 modes that run at 59.95 Hz and at 74.97 Hz. So it sounds like if the M1 Mini only offers 59.95 / 60 Hz, the monitor would be willing to take it.

The long answer is highly technical and would require speculating about Apple engineering design, which over here is forbidden. Short answer: it is what it is. Sorry!