Mac Mini (M1) dual display doesn't work.

I don’t buy this for a second. Apple have been running multiple monitors across multiple graphics cards from different manufacturers in mixed bit depths, refresh rates, and resolutions since at least 1987.

What we are seeing here is straightforward bugginess, of a kind usually reserved for Windows setups, where multiple monitor support has been around for a far shorter period, and has had nowhere near macOS’ capabilities. Also we’re not just talking about multiple monitor problems; it’s mainly about connections using anything except the built-in HDMI port; even single monitors are having problems via direct usb-c or via adapters.

michaenh wrote:

Apple have great products and I do have several Apple products from pad, phone, laptop and so on.

First time meeting and experience are very important.

I’m sure Apple knows this.

If not, they will relearn it, I expect.

Hi Alastair

Thank you for that, and the time it took you to put together.

All good but however, I don't think expecting two monitors to work (as the main blurb says they will) is much of a reach as far as tech expectation goes. I even bought 2 x new 4k monitors from a well known brand to go along with it so there is nowhere for Apple to hide as far as some bizarre compatibility issue goes.

It also worked fine with the seven year old Intel chip so it's not like we're breaking new ground here.

Even the £70 Apple adaptor didn't do it.

However, you look at it, it's not good enough.

I sent my Mini back after a month as, as a developer, I need at least two screens to be productive. I will probably get a Mac Mini when the next generation comes out and I am sure that it actually works properly (Bluetooth as well as external screens). Objectively, I think that it is so weird how many people on this forum have been willing to make excuses for Apple; it's all the classic lines from an abusive relationship. It is their fault. Every single other device I own has been able to drive my two screens (The Lenovo Chromebook ThinkPad C13 I bought as a stopgap runs a Ryzen 3500 chip which is new with Chrome OS and yet it is still able to drive 3 external monitors). Even the Raspberry Pi 4 is able to do it. I honestly think that the M1 chip is a phenomenal advance and will drive increased advances in the chip world (although I really don't think AMD is getting enough credit for what it is doing). Nevertheless, that is not excuse for Apple's complacency and willingness to take its user base for granted (although, judging from this thread, they know their audience).

To be clear, I’m not trying to make excuses for Apple. I do, however, think that there are a number of genuine compatibility issues that are clearly causing confusion and need explaining, hence my post.

Alastair thanks for the deep technical explanation and I am guilty of trying a bunch of adapters as well, however it is WELL documented that even people trying to use this machine as Apple intended (HDMI and USB-C) for dual monitors still have trouble getting an HDMI monitor to work well and stay working with a second monitor plugged in to the USB-C port.

I'd much prefer to stay with a future proof machine such as the M1 Mac mini, however Apple has released 2 major OS updates and neither has fixed this issue for almost all of us on this forum making it hard to justify continued use of this machine. I honestly wish I had just gotten the Intel version at this point cause I'd have two monitors and I can easily justify converting the Intel mini into an office server down the road.

1 cable is HDMI from the mac mini to monitor one.

Then I have a Mini DisplayPort to DisplayPort Cable connected to my OWC Thunderbay 4. The Thunderbolt 4 from OWC has a DisplayPort Cable socket on the back of it's enclosure. The OWC Thunderbay 4 is connected to the mac mini via a Thunderbolt cable.

Really? I’ve my second monitor sitting idle because I just don’t have the time for this any more. Working with one monitor is a complete pain in the @ss too.

What cables are you using?

I’m guessing the first one is hdmi from mac m1 mini to hdmi monitor?

And the second?

Thanks so much! I thought I had a bad Mac Mini -- BUT surprise! We all do! So ... I saw the 'flickering' video - I had that - found a way to get by it ... Here's what I have connected to my 3.2Ghz-6Core Intel i7 with Intel UHD Graphics 630 1536MB - I've no solutions to add to this thread but I wanted to share the same struggles ...

1. Kamvas Huion 13" 1080p tablet/monitor ... connected into a mini-display port via HDMI to USB-c (not sure the quality of the connector) ... works fine though ...
2. An old Haier 1080p 40 inch TV also connected into a mini-display port via HDMI to USB-c (again, not the quality of the connector) ... works fine though ...
3. A newish 4k HiSense TV connected directly to HDMI on the Mac Mini ... works GREAT! - when it works ... (this solved the flickering)

So here are the remaining struggles ... (and I'm running Big Sur 11.2.3) ...

1. It's a crap shoot as to which monitor becomes my main display on reboot UNLESS I power off both my TVs and boot so that the Kamvas Tablet/Monitor is the only USB device. I think there must be a 'powering up' order for the TVs that might fix this ... No matter, I presently leave the computer on most of the time ... if I let only the monitors go off/dim sleep ... it seems to be aok (NOT the Kamvas) ... when the TVs are turned on ... it's just the Mac Mini that you have to keep alive ALL THE TIME. I 'un-enabled' the power nap option in Energy saver just today - so I'll see what happens ... so the computer doesn't nap - just in case i.e. I've stopped shutting down & restarting my Mac ...
2. Often ... I lose my 4k TV on start-up - just does not detect it ... so I used to boot / reboot etc. often (not anymore cause I don't turn the computer off).
3. Now - when the computer and monitors all work together - and they do - I fiddle til they do - yes ... I love my Mac - It's fabulous to have the large screen-scape - I can do all my former dual-display work in just the one 4k TV/monitor ... I deliver my lectures simultaneously using the tablet ... and in the third display I have my mail, calendar, messages etc ... It's really nice when it works ... I'm only a bit frustrated with the fiddling I've had to do ... for example ...

PS: There is another issue - not sure when it came about - but the Mac Mini doesn't always connect my BT Mac Wireless keyboard and mouse. When this fails - login fails too even when I use a USB keyboard/mouse combo (I have to reset my password via my Mac account - THIS IS THE STRANGEST thing ever). I'm thinking I have a few BT devices competing to be paired with the Mac OR more likely, I need to re-install Big Sur). BUT when the BT keyboard works ... so does login ... this one is such a puzzle for me just now ...

Apple probably will never fix this. I've had issues with my displays on my 2012 Mac Mini and it's never been resolved. Somehow Apple is unable to do basic things that every other computer manufacturer has seemingly little issues with- support the use of external monitors... Even more sad considering Apple writes it's own operating system and uses it's own hardware, still can't get it right.

i have a Mac Mini 2018 Intel and lost the HDMI port after update to Big Sur. I have tried every available Big Sur release including developer. I wouldn't count on downloading a beta resolving the issue for Intel Mac Mini 2018. People report wonderful things happening with betas that may not be confirmable. For me, even with 3 displays down to 2 Big Sur is a more stable improvement over Catalina. There are always various Recovery mode options to reinstall the last OS that worked with a particular setup and this could be the most elegant solution.

I saw a tip on MacRumors that worked for my issue above--I reset SMC to reset power supply issues. Shut down my Mac Mini 2018, pressed the start button for 10 seconds (chime) and released. Then, after a pause, I pressed start again to restart the Mac Mini and my Mac recognized the third display (Samsung 4K tv) on the HDMI port. Could be resetting SMC will help with other issues people are having after updates to Big Sur.

Just updated to Big Sur 11.3 on my Mac mini M1, still only one monitor works. Even worse, only works via USB-C port to mini-display adapter. The HDMI port no longer works (with my adapters no idea with an HDMI monitor..). It seems dual display support is never happening from Apple on these things, real shame. Probably return the mini for the new iMac and see if I can get a second display powered from it.

tried USB-c to display port on a 34" superwide screen. Not working!

HDMI output works on same display.

Waiting for USBc to HDMI adapter to arrive to test if I can use it on a 1080 Samsung tv (which works using the Mac mini HDMI out)

Well this is irritating. I got my replacement Mac Mini yesterday so this is day 1 using it. I walked away for a bit and when I came back and unlocked my computer- I noticed nothing was open on my right monitor. That's because Mac OS moved everything to the primary monitor. So unless there's a way to fix this, every time I come up I have to move the windows back to where I want them?

You've got to be kidding me, Apple...