Using your iMac as screen for Mac Studio

[albertdros]

I've been on the fence about getting a new iMac for a while already, and now with the newly announced Mac Studio I think I'm just going to get that.

But it would be great if Apple would let us use our older 27 inch iMacs simply as a screen for the Mac Studio. I think they did that with the very old generations of iMac. And now that it seems that the 27 inch iMac will be discontinued (not sure ofcourse), it would be nice of apple to allow this via software.

Thoughts? The 27 inch iMac is a beautiful screen. It would be a shame to not put it to good use.

 

[PBG4 Dude]

This stopped being possible when Apple went to 5K displays on their iMac. Internally, the 5K display is treated as two displays welded together. There are custom Apple display chips in the iMac to make this setup possible. There is no way to feed an appropriate signal to the display via Thunderbolt because Apple has made it not possible to do so.

You can airplay from one Mac to the other via macOS, but there will be lag. Whether or not the lag is too much depends on what you’re doing.

 

[zoran]

What about iMacs without a 5K display? For example my 27" mid2010 iMac

 

[Puonti]

You can read about the requirements here:

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

Simplified, Macs introduced in 2019 or earlier, running Catalina or earlier, can use iMacs introduced between 2009 and 2014 as displays.

I've tried it a few times back in 2010-2011 by connecting an original Xbox to my 27" iMac with an HDMI to DisplayPort converter and while it worked it did not come across as a great experience. The iMac being used as a display must be booted into macOS and running in the background while it's being used as a display. That seems quite energy inefficient to me, and obviously does not allow extending the useful life of "dead" iMacs as displays.

I don't see incentives for Apple making this possible with newer Macs.

 

[bsbeamer]

The lack of target display mode on my 2019 27" 5K screen is personally holding me back from starting the transition to AS models. Zero value with Apple for trade-in towards a new display. In all honestly, probably would have more seriously considered a Studio model on pre-order if I could reuse this retina 5K screen or even boot into a separate "monitor OS" that runs the machine as a TB display.

The only Apple-based solution that could come close to working is to use the 27" 5K as an AirPlay display... and anyone who's done that from an MBP or another machine will tell you it works in a pinch or for some spreadsheet style work, but it is not even close to a solution to be used for visual work. The display compression and artifacts are worse than trying to drive 4K/5K over USB with DisplayLink (instead of using TB with more bandwidth). It's almost an amazing achievement they're able to do it wirelessly with the fidelity it has, but it cannot be relied on as a main display at all.

There is zero reason the computer needs to be bundled with the display moving forward, especially if it's a single (or even double) cable connection to achieve near all-in-one. Get a TwelveSouth style BackPack shelf to toss the machine on it if you truly cannot stomach seeing a computer off to the side.

In the meantime, I'll still keep an eye on future solutions or hacks that are semi-achievable for the normal person. Short of that, I'd probably sell, just keep it, or maybe even donate to family or someone local. Sucks to even have to consider "tossing" the retina 5K display just because it lacks an input method. For all the eco-conscious sustainability garbage Apple touts, this should have been addressed, somehow.

 

[Sunbound]

Fully agree!
Want to upgrade to the Studio but also want to keep the iMac 27".
If Apple had made it possible to connect and let me switch between i the Studio and the iMac I would have purchased already...Not really keen on investing in a new display as the current 27" 5K resolution is more than enough.

 

[bingeciren]

Anybody tried Luna Display yet?

 

[bsbeamer]

Anybody tried Luna Display yet?

Have previously, not recently. It was more reliable than Apple Sidecar, but largely is not a substantial or major visual quality improvement. Uses pretty heavy display compression and operates over WiFi. Latency can improve vs. the Apple solutions and usually is more acceptable, but if you're trying to use in an office setting or more crowded WiFi space it does get laggy. Personally think this is more of a solution for a temporary or wireless 2nd/3rd screen than a full-time main display.

 

[bingeciren]

Have previously, not recently. It was more reliable than Apple Sidecar, but largely is not a substantial or major visual quality improvement. Uses pretty heavy display compression and operates over WiFi. Latency can improve vs. the Apple solutions and usually is more acceptable, but if you're trying to use in an office setting or more crowded WiFi space it does get laggy. Personally think this is more of a solution for a temporary or wireless 2nd/3rd screen than a full-time main display.

It works wired as well. Ethernet or Thunderbolt cable to connect in Mac-to-Mac Mode, or connected via a router. I don't own one but people testing it this way shows the latency is in few milliseconds, in other words practically imperceivable.

 

[bsbeamer]

It works wired as well. Ethernet or Thunderbolt cable to connect in Mac-to-Mac Mode, or connected via a router. I don't own one but people testing it this way shows the latency is in few milliseconds, in other words practically imperceivable.

I've never used or tested wired. Seems in the best case scenario for most this would get iMac to work as a secondary display. Probably at least need a small monitor as backup or for initial setup.

 

[bingeciren]

I've never used or tested wired. Seems in the best case scenario for most this would get iMac to work as a secondary display. Probably at least need a small monitor as backup or for initial setup.

 

[bingeciren]

I’ll get one soon and use our 2014 iMac as a 5k display with a new M1 Mac Mini.

 

[Nguyen Duc Hieu]

The lack of target display mode on my 2019 27" 5K screen is personally holding me back from starting the transition to AS models. Zero value with Apple for trade-in towards a new display. In all honestly, probably would have more seriously considered a Studio model on pre-order if I could reuse this retina 5K screen or even boot into a separate "monitor OS" that runs the machine as a TB display.

The only Apple-based solution that could come close to working is to use the 27" 5K as an AirPlay display... and anyone who's done that from an MBP or another machine will tell you it works in a pinch or for some spreadsheet style work, but it is not even close to a solution to be used for visual work. The display compression and artifacts are worse than trying to drive 4K/5K over USB with DisplayLink (instead of using TB with more bandwidth). It's almost an amazing achievement they're able to do it wirelessly with the fidelity it has, but it cannot be relied on as a main display at all.

There is zero reason the computer needs to be bundled with the display moving forward, especially if it's a single (or even double) cable connection to achieve near all-in-one. Get a TwelveSouth style BackPack shelf to toss the machine on it if you truly cannot stomach seeing a computer off to the side.

In the meantime, I'll still keep an eye on future solutions or hacks that are semi-achievable for the normal person. Short of that, I'd probably sell, just keep it, or maybe even donate to family or someone local. Sucks to even have to consider "tossing" the retina 5K display just because it lacks an input method. For all the eco-conscious sustainability garbage Apple touts, this should have been addressed, somehow.

The LCD driver board to drive the LG 27" 5k LCD on your iMac cost about 250~300$.
a totally easy DIY project for the weekend, if you do care about the environment.
You can sell the iMac logic board to cover the cost of the LCD driver board.

 

[costica1234]

It works wired as well. Ethernet or Thunderbolt cable to connect in Mac-to-Mac Mode, or connected via a router. I don't own one but people testing it this way shows the latency is in few milliseconds, in other words practically imperceivable.

Wow, I had no clue this was possible. A quick search even revealed a MR thread, the most relevant post being https://forums.macrumors.com/thread...ode-5k-support-and-more.2325796/post-30711109.

The only limitation is that it runs at 5K45Hz instead of 5K60Hz (this is clearly specified here: https://astropad.com/luna-display-5-1/).

 

[bingeciren]

Wow, I had no clue this was possible. A quick search even revealed a MR thread, the most relevant post being https://forums.macrumors.com/thread...ode-5k-support-and-more.2325796/post-30711109.

The only limitation is that it runs at 5K45Hz instead of 5K60Hz (this is clearly specified here: https://astropad.com/luna-display-5-1/).

Breath new life into otherwise obsolete iMacs. Better than shelling out $2k for a studio display if you happen to own an iMac.

 

[bsbeamer]

Breath new life into otherwise obsolete iMacs. Better than shelling out $2k for a studio display if you happen to own an iMac.

Valid option for some, especially as a second monitor. Still issues to use as primary, especially for design, video and possibly even some audio depending on plugins being used and precision expected. Probably perfect for spreadsheets and more document based work.

As long as you have access to another physical display in case of emergency or issue, worth it for many to at least explore or test. Example, might need a physical display connected during firmware updates.

 

[BillyBurke]

Boy, finding a simple "yes or no" answer is seemingly impossible these days. Can I use my 2019 21" iMac as a monitor by simply plugging a cable from the Studio to one of the Thunderbolt ports on the iMac?

 

[bsbeamer]

Can I use my 2019 21" iMac as a monitor by simply plugging a cable from the Studio to one of the Thunderbolt ports on the iMac?

NO

 

[alfansome]

What about iMacs without a 5K display? For example my 27" mid2010 iMac

The following steps worked for me to use my 2010 iMac (high sierra 10.13.6) as primary or secondary display for Mac Studio:

(1) boot the iMac but do not log in
(2) connect iMac mini-display port to Mac Studio usb-c (thunderbolt) port using mini-display to usb-c cable*
(3) boot Mac Studio computer; iMac now shows as primary or secondary display; of course resolution is limited to that of the display in the iMac

* The cable I used was purchased from Amazon: Answin USB-C (thunderbolt 3) to Mini-Display, approximate cost $16

 

[planetMitch]

Boy, finding a simple "yes or no" answer is seemingly impossible these days. Can I use my 2019 21" iMac as a monitor by simply plugging a cable from the Studio to one of the Thunderbolt ports on the iMac?

When I was in the apple store recently, the Mac genius told me I could connect a Mac studio to my 2019 iMac and use the iMac as the main monitor. I don't have a Studio yet so I haven't tried it.

This article seems to say YES

How to Set up Mac to iMac Dual Monitors

Want to use your iMac's awesome screen as a monitor for your MacBook or Mac desktop? If you're using a newer iMac running macOS Monterey, it's easy to use AirPlay to mirror or extend your screen to an iMac. For older iMacs running High...

www.wikihow.com

 

[theorist9]

The two solutions I know of are Astropad's Luna Display and Apple's AirPlay. Last time I read the reviews, neither worked optimally (but they may be good enough for your purposes). With AirPlay, you get the best performance when running a wired connection, but there's still some lag (less lag than with wireless, though), and you don't get the full 5k resolution. [Again, this is from the last time I checked—things might have improved since.]

MR Luna Display thread:

Luna Display Gains PC-to-Mac Mode, 5K Support and More

The Luna Display dongle that's meant to turn an iPad or Mac into a secondary display for a primary machine today received a major 5.1 software update, introducing new features. With the new PC-to-Mac Mode, Luna Display owners can turn a Mac into a secondary display for a PC. PC-to-Mac mode...

forums.macrumors.com

MR AirPlay thread:

Newer Macs Can Use Another Mac as an External Display on macOS Monterey

One of the key new features of macOS Monterey is the ability to AirPlay content to a Mac from other Apple devices, such as an iPhone, iPad, or...

www.macrumors.com

 

[carl varley]

I use screen sharing over Ethernet on a M1 Mac mini to 2011 iMac but works well via thunderbolt too. A hdmi dummy is needed for gpu acceleration, these cost around £5-10 on Amazon and has a frame rate of around 30fps. Newer hardware may be better I haven’t tested it on anything else. The good thing about it is you use the iMac as well. You can view the shared computer in a window or full screen, share files with drag and drop share a clipboard and share a mouse and keyboard.

 

[JacquesleMac]

The following steps worked for me to use my 2010 iMac (high sierra 10.13.6) as primary or secondary display for Mac Studio:

(1) boot the iMac but do not log in
(2) connect iMac mini-display port to Mac Studio usb-c (thunderbolt) port using mini-display to usb-c cable*
(3) boot Mac Studio computer; iMac now shows as primary or secondary display; of course resolution is limited to that of the display in the iMac

* The cable I used was purchased from Amazon: Answin USB-C (thunderbolt 3) to Mini-Display, approximate cost $16

Would this work with a late 2014 5K 27-inch iMac running Catalina? If it does I’ll order a Mac Studio tomorrow!

 

[carl varley]

Would this work with a late 2014 5K 27-inch iMac running Catalina? If it does I’ll order a Mac Studio tomorrow!

No, the 2010 iMac supports "display port in" and was discontinue with this model. The 2011 onwards uses thunderbolt as "target display mode", until your 2014 model discontinued that.

 

[JacquesleMac]

No, the 2010 iMac supports "display port in" and was discontinue with this model. The 2011 onwards uses thunderbolt as "target display mode", until your 2014 model discontinued that.

Damn, I had car keys and wallet in hand. But thanks for the info.