I was able to repurpose my 2011 27" iMac with M1 Mini using Luna display over thunderbolt. I don't believe it works with Retina imacs however.
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Newer Macs Can Use Another Mac as an External Display on macOS Monterey
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This is what I thought, however M1s/Big Sur? doesn't support target display mode. Doesn't work with my M1 to 27" iMac 2011.
I use a Luna display and it is unusable over Wifi and ethernet. Too much latency and compression blocking for me. It is solid over thunderbolt bridge.
So not hardwired, it's comparable to airplaying or sidecaring. Perfectly fine for second screen tasks, emails, spreadsheets whatever. But anything with animations like minimizing a finder window, dragging windows around, etc you'll notice a bit of blocking and latency.
But I'm using my 27" as my main screen with my M1 mini, so I need it latency free for video editing. Over thunderbolt bridge, and once the bandwidth gets cranking up after a couple minutes, I'll put it at 90-95% a true monitor. More than adequate as a monitor replacement, and I get to keep my old iMac for legacy stuff.
I made a blank user, the app automounts, it's not connected to the internet, so it runs silent and cool. Only quirk is the monitor won't sleep, but I just use a black screen saver instead. It also won't play iTunes protected video content (Cinema display won't either, I think due to the dongles).
Target Display Mode does work on 27" 2009-2010 iMacs with M1 Macs and/or Big Sur as the source, since it's mini-DisplayPort (not Thunderbolt).
Like I said, you can even use Windows machines as the source for Target Display Mode with 27" 2009-2010 iMacs.
I don't have an M1 Mac on hand, but other people have already confirmed it works. I do have a Big Sur Mac on hand though. Here's my 2017 iMac Big Sur with 2010 iMac in Target Display Mode.
Apple claims that a 2019 or earlier Mac is required as the source, and it must be running Catalina or earlier, to get Target Display Mode to work on the 2009-2010 iMacs. However, this is obviously a lie, as my screen grab above and this M1 Target Display Mode thread demonstrates.
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The cutoff for the connecting computer must have Catalina or earlier on it, and have been introduced in 2019 or earlier (not M1s). Are you running an M1 to your 2010 iMac over TDM now?
iMac models introduced in 2011, 2012, 2013, and mid 2014
To use any of these iMac models as an external display:- The iMac used as a display must have macOS High Sierra or earlier installed.
- The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
- The cable connecting the two Mac computers must be a Thunderbolt or Thunderbolt 2
cable.
24-inch and 27-inch iMac models introduced in 2009 and 2010
To use any of these iMac models as an external display:- The iMac used as a display must have macOS High Sierra or earlier installed.
- The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
- The cable connecting the two Mac computers must be a Mini DisplayPort cable.
Use your iMac as a display with target display mode - Apple Support
Target display mode is a feature available with certain older Mac models.
See my post above and check out my screen grab. (I edited the post just as you posted yours.) Apple's info page is simply wrong at best, a lie at worst. I'm running Big Sur on an Intel Mac and it works fine, and others have already confirmed it works fine on M1 Macs, too... but only with 2009-2010 iMacs.The cutoff for the connecting computer must have Catalina or earlier on it, and have been introduced in 2019 or earlier (not M1s). Are you running an M1 to your 2010 iMac over TDM now?
iMac models introduced in 2011, 2012, 2013, and mid 2014
To use any of these iMac models as an external display:
- The iMac used as a display must have macOS High Sierra or earlier installed.
- The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
- The cable connecting the two Mac computers must be a Thunderbolt
or Thunderbolt 2cable.24-inch and 27-inch iMac models introduced in 2009 and 2010
To use any of these iMac models as an external display:
- The iMac used as a display must have macOS High Sierra or earlier installed.
- The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
- The cable connecting the two Mac computers must be a Mini DisplayPort
cable.Use your iMac as a display with target display mode - Apple Support
Target display mode is a feature available with certain older Mac models.support.apple.com
Just an Update for MacRumors....
I have a 2017 iMac Pro and an M1 mini running Monterey and I can use AirPlay for them both. So your statement that indicates AirPlay only for 2019 iMac Pro should state at least 2017 iMac Pro. Just saying....
Whoops, just re-read what you posted and you did state for any iMac Pro..... sorry ... my bad.
I have a 2017 iMac Pro and an M1 mini running Monterey and I can use AirPlay for them both. So your statement that indicates AirPlay only for 2019 iMac Pro should state at least 2017 iMac Pro. Just saying....
Whoops, just re-read what you posted and you did state for any iMac Pro..... sorry ... my bad.
You’d think Apple would be all about the repurposing of old computers (TDM), considering how much they squawk about how “green” they are.
There are SO MANY 4K/5K iMacs like yours that have a beautiful display, but are collecting dust in a closet or attic.
Here's an example use case: be me. Most of the time, I prefer working on a single MacBook display, because that way, I have the same setup wherever I am.
However, as a developer, I sometimes have to implement and test multi-display functionality. Other times, I have to test stuff on future macOS versions that I'm not using on my main work Mac yet. A second Mac — say, a base-configuration M1 iMac — connected either via AirPlay or Universal Control, depending on what I'm trying to do at the moment, can serve both of those purposes. Better yet, I can switch between those two scenarios on the fly. That means I get away with having one fewer device on my desk. That's a tempting prospect, because I don't like clutter.
And if you're the superficial type like me, who prefers the look of Apple devices over, say, the plasticky look of Ultrafine displays, there's a bonus: By using an iMac via AirPlay, I get a nice Apple-designed external display (of sorts) without having to shell out $$$ for the XDR display.
Long story short, by introducing AirPlay for Mac, Apple just sold an iMac to me. I get that this isn't for everyone, but for me, this is the best new macOS feature in years, and it works even better for me than target display mode would.
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Doesn't seem to say there will be screen mirroring from mac to mac.
If read carefully, you can airplay content from an iPhone/iPad/Mac to a Mac but when mirroring a display it only says iPhone/iPad to a Mac.
I'm assuming they won't be doing something like Target Display Mode because they want you to buy a whole new mac if you want the newest internals built into a Mac form factor. Rather than just buying the Mac Mini and using an older Mac.
If read carefully, you can airplay content from an iPhone/iPad/Mac to a Mac but when mirroring a display it only says iPhone/iPad to a Mac.
I'm assuming they won't be doing something like Target Display Mode because they want you to buy a whole new mac if you want the newest internals built into a Mac form factor. Rather than just buying the Mac Mini and using an older Mac.
Airplay from iPadOS to Mac shows that Apple needs to fix iPadOS so it displays properly on a 16x9 or 16x10 monitor without the black bars to the side.
Eyoyo sells 4K monitors at 15.6 inches. So that's 280+ppi, higher resolution than many MacBooks.
... Or screen-sharing your personal Mac to your work colleagues via VPN or some "work-only" teleconference app — perhaps to show a mac app that's not yet approved by corporate.
Which have you tried? I have spent days trying to get my MBP 2020 to connect, to no avail; it seems they removed the support from that generation onwards.
I made the right choice when selling my 27” iMac from 2016 and replacing it with an Air… but indeed, an uncompressed, latency-free feed would suddenly make aging iMacs a lot more valuable, especially considering the dearth of comparable high-ppi 4K or 5K monitors in the market for any price, really.