You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Using Mid-2011 27” iMac as a second display for a 2021 M1 iMac

Is it possible to use my Mid-2011 27” iMac running Sierra as a second display to extend the deskto of my new 24” M1 iMac.


I am connecting the two computers using a Thunderbolt 2 cable with an Apple Thunderbolt 3 to Thunderbolt 2 adaptor.


My mid-2011 iMac does not have a Mini-DisplayPort. My new 2021 iMac is the larger capacity model with two Thunderbolt and two USB-C ports.


I tried this configuration and nothing happens when I press Command F2 on the older Mac. Others seem able to do this to extend the screen of their MacBooks and provide a second display of their Mac Mimi’s but I don’t know why this wouldn’t work with one of the new M1 iMacs.


If this is not feasible, are their alternative ways to connect the older iMac as a second display?



iMac Line (2012 and Later)

Posted on Aug 9, 2021 5:27 PM

Reply
Question marked as Top-ranking reply

Posted on Aug 9, 2021 5:51 PM

Please read Target Display Mode (Target Display Mode) ,it indicates:


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.



Your 2021 M1 iMac is too new and in case you were wondering...no it cannot have macOS Catalina installed on it.

Similar questions

4 replies
Question marked as Top-ranking reply

Aug 9, 2021 5:51 PM in response to timbucktu

Please read Target Display Mode (Target Display Mode) ,it indicates:


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.



Your 2021 M1 iMac is too new and in case you were wondering...no it cannot have macOS Catalina installed on it.

Aug 10, 2021 6:57 PM in response to rkaufmann87

@RKauffmann87, Thanks for confirmation of Jack-19’s assessment. Added thanks for taking the time to share an explanation.


I bought what is now my fourth generation of iMacs as my ten year old edition was having some odd display issues and has been dead-ended on Sierra for years thus eliminating upgrades to a number of software products. The machine had actually been performing really well after I started booting from an external SSD.


The ten year old 27” display is still quite remarkable and the new 24” M1 iMac’s smaller display seems cramped as they sit next to each other. Alas, I guess it’s time to donate/recycle that faithful machine. 🙂


tim

Using Mid-2011 27” iMac as a second display for a 2021 M1 iMac

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.