3 x monitors on the M1 Mini (HDMI + DVI x 2)

Officially the M1 Mac Mini only supports two displays. One on the HDMI port and one on a USB-C/Thunderbolt port.

see > https://support.apple.com/guide/mac-mini/connect-a-display-apd8e4fbbb97/mac

So even if you can find and make a Dock or splitter work, those two displays will only be mirrored and not extended.

Well, according to Apple, the M1 Mac mini can only support up to two (2) external display no matter how you connect them.

Video Support

• Simultaneously supports up to two displays:
• One display with up to 6K resolution at 60Hz connected via Thunderbolt and one display with up to 4K resolution at 60Hz connected via HDMI 2.0

Ref: https://support.apple.com/kb/SP823?viewlocale=en_US&locale=en_US

I have three monitors connected to a 16 GB M1 Mac mini in my flight simulator. There are also two additional iPad connected to it. The system is as follows:

X-Plane 11.55r2 on a 16 GB M1 Mac Mini connected: 

(1) To a Dell model 2007 FPS monitor (1600 x 1200 @ 60 Hz via VGA on monitor to VGA/DVI-I adapter to Startech.com USB 3.0 Dual Head Graphics Adapter to USB-C on Mac Mini), and 

(2) to a Westinghouse TV model LDD2240 (1920 x 1080 @ 60 Hz via HDMI to HDMU), and 

(3) to a Flatron W2252TQ (VGA ơn monitor to Belkin VGA/Thunderbolt adapter to Thunderbolt on Mac Mini)

DisplayLink driver from Startech.com was loaded and activated. OS is Big Sur 11.4.  Logitech Saitek Yoke, Power Quadrant, Rudder Pedals, and Radio Stack.  Flight Velocity Pro Trim Wheel.  Mini iPad with ForeFlight is mounted on the yoke and provides GPS position on a map (VFR, IFR, or Satellite).  Another mini iPad with Air Manager V.3.7 from Sim Innovations shows the instrument panel, and allows one to have only external views on the three monitors. I often switch to that view AFTER completing pre-takeoff checklists and getting underway.

I should have mentioned above that the images are not mirrored in the three monitors. One show the instrument panel and the front windscreen, and the other two are views out the left and right windows of the plane. X-Plane allows the user to have the monitors display different horizontal and vertical angles from the forward view.

(Continuing from above)

the DisplayLink driver can be downloaded from the Startech.com website. They are also the source for the connector that you need. They have excellent technical support, so don’t hesitate to call them.

Be aware that there is another company with a very similar name, but I believe I got it right.

The part number is USB32HDDVII and it is from Startech.com.  It cost about $83 when I bought it.  The full title on the box is “USB 3.0 Dual Head GraphicsAdapter - HDMI and DVI-I”.

The box contains USB 3.0 to HDMI/DVI-I Graphics Adapter / Mini USB 3.0 Cable / DVI to VGA Adapter / Driver CD / Installation guide.  I also had to download and activate the DisplayLink driver from Startech.com.

The M1 Mac mini may not turn on all three monitors immediately.  I find that it often takes 30 - 60 seconds before the 3rd one lights up.  Depending on the program you are using, you may have to trick the M1 Mac mini into recognizing that there are three monitors connected.  With X-Plane, I got only two monitors working the first time I tried the system.  I went to System Preferences, then screens, and designated the monitor that had not activated as the main monitor.  When I restarted X-Plane, all three monitors were recognized.  After that, I redesignated which one was the main monitor and set the geometry within X-Plane.  I have not had to do that since.

Don’t be a nervous Nellie or an impatient brat if everything does not work immediately.  You are dealing with a smart computer, and it and your software are probably using artificial intelligence, so they may be learning as you go.  Don’t treat it like an adding machine.

Let us know how it works out in your system.  X-Plane is very demanding where CPU and GPU are concerned, but my system works.

I am away from home at the moment, but will send you the link when I get home. Be aware that you will also need the DisplayLink driver. It can be downl