Target display mode
Can I use my old late 2012 iMac running on high sierra as a display for my pc if I use a mini dp to dp cable
Can I use my old late 2012 iMac running on high sierra as a display for my pc if I use a mini dp to dp cable
No, that setup is not supported by Apple. The iMac cannot be used as a monitor for any of the newest Macs and Target Display mode is no longer a feature of macOS, having been deprecated several years ago. TDM was never supported for use with any other PC.
Please see: Use your iMac as a display with target display mode - Apple Support
The two DMs are running Catalina, and the driving machine is running Ventura.
The setup is largely faultless, but there have been more stable versions of TDM on the other iMac when running both Catalina and Ventura. The target displays have always run Catalina.
Overnight my main computer (2019 iMac) updated itself (which it is set to do, but never normally does 🙄) to Sonoma.
With my configuration, the TDM still operates with the two 2012 TDs running Catalina. So in this case (at least) all is right with the world. Though it is not on Apple's radar, the TDM is one of the most appreciated functions offered by Apple, and is invaluable to both my research and aesthetic preferences; more screen realty (a bigger screen) is not better when you use computers for academic work (research, writing, teaching, online instruction, and academic publication), in which you need multiple screens to separate search browsers, .pdfs, e-mails, and Pages).
If the next OS fails to support TDM, I am not at all sure what I will have to do -- presumably, one would be forced to buy a Mac Mini and three Apple monitors (which are too big for my desk). I am not even sure if a Mac Mini would drive three Apple 4k monitors. In this respect, Apple's direction is less good.
I have a MacBook Pro with two 2013 iMac 27" computers that I use in Target Display Mode. I just updated the MBP and one of the two iMacs to Sonoma. The other iMac is still on Ventura. (yes both iMacs run OpenCore Legacy Patcher). Only the iMac still on Ventura reacts when I press cmd+F2 to activate TDM. So it seems like Sonoma can still act as the main computer but the "slave" computer must remain on Ventura in order to use TDM in this kind of setup. If anyone finds a way to use a slave computer running Sonoma OS please do post the solution here!
Target display mode