I have an MB Pro 13” purchased in 2015 that I want to hook up to 21” iMac purchased in 2011/2012. From what I’ve read, I need a Thunderbolt to Mini DisplayPort cable to make this work. I do not see such a cable online, but see ones that go the Mini DisplayPort adapter with an HDMI port on the other end.
Can the HDMI port transmit the necessary signal to the iMac to make this work?
MacBook Pro 13″, macOS 11.7
Good morning!
To see the very restricted hardware and system software requirements for what you are attempting—Target Display Mode—please see this Apple tech article:
Use your iMac as a display with target display mode - Apple Support
1) Your video source—the Macbook Pro that appears to be running macOS 11.7—would require its system be downgraded to 10.15 Catalina to be the video source for a TDM-support iMac.
2) "....hook up to 21” iMac purchased in 2011/2012. ...." Can you be more specific by doing "About this Mac..." on the iMac? 2010-2011 represented a change in TDM requirements and a purchase date does not necessarily covert to the sub-model name which Apple uses to establish compatibility.
Example of where to find SUB-MODEL from "About this Mac..."
For an iMac with a mini-display port, the typical (and successful) connection arrangement is:
video source from 2015 Macbook Pro > thunderbolt cable > thunderbolt to mini-display port adapter > 2011 iMac
NB: Please consider a free-standing external monitor instead. The last time I checked, the required cabling and adapter to do what you want could cost between US$60 and US$90! 😳 Also you would not have to downgrade the OS on your Macbook Pro to use a regular external monitor. Some TDM setups are limited to mirrored only; if you need extended desktop combined with lower power consumption, get the external and wish the iMac a happy retirement.
You are doing archeology with TDM. Apple began its deprecation in Late 2014 and threw the last shovel of dirt in its face in early 2020. Dr. McCoy said it best:
Good morning!
To see the very restricted hardware and system software requirements for what you are attempting—Target Display Mode—please see this Apple tech article:
Use your iMac as a display with target display mode - Apple Support
1) Your video source—the Macbook Pro that appears to be running macOS 11.7—would require its system be downgraded to 10.15 Catalina to be the video source for a TDM-support iMac.
2) "....hook up to 21” iMac purchased in 2011/2012. ...." Can you be more specific by doing "About this Mac..." on the iMac? 2010-2011 represented a change in TDM requirements and a purchase date does not necessarily covert to the sub-model name which Apple uses to establish compatibility.
Example of where to find SUB-MODEL from "About this Mac..."
For an iMac with a mini-display port, the typical (and successful) connection arrangement is:
video source from 2015 Macbook Pro > thunderbolt cable > thunderbolt to mini-display port adapter > 2011 iMac
NB: Please consider a free-standing external monitor instead. The last time I checked, the required cabling and adapter to do what you want could cost between US$60 and US$90! 😳 Also you would not have to downgrade the OS on your Macbook Pro to use a regular external monitor. Some TDM setups are limited to mirrored only; if you need extended desktop combined with lower power consumption, get the external and wish the iMac a happy retirement.
You are doing archeology with TDM. Apple began its deprecation in Late 2014 and threw the last shovel of dirt in its face in early 2020. Dr. McCoy said it best:
You are most welcome. Thank you for the followup.
With those specs you could theoretically do Target Display Mode IF you downgrade the Macbook Pro to Catalina and have no issue with the high cost of cabling/adapter.
However, I should add that TDM was never a slam-dunk once ThunderBolt Macs came out. I've handled plenty of posts here where the user had the "right" gear and system software and still struggled to get TDM working.
This would be a temporary setup until I replace the iMac with a new one
Just checking: You realize that new iMacs cannot support TDM?
Thanks for the feedback - The MacBook Pro (Retina 13" Mid-2014) is running Big Sur, (11.7) the iMac (21.5-inch, Mid 2011) is running High Sierra (10.13.6).
This would be a temporary setup until I replace the iMac with a new one, and give the MBP to my grandkids
I inherited the MBP, and have used the iMac for more than 10 years…a new iMac would be a stand alone device but I’m not ready to buy one just yet
MacBook Pro using an iMac as a monitor
