Question: Connecting iMac (mid2011) as second display to iMac 2017
I'm trying to connect my older iMac 27" (mid-2011) as a second display to my new iMac 5k 27" (2017). It seems "target display" is no longer an option. I purchased a USB-C to MiniDP cable and tried connecting my new iMac to the older one without any success. I also tried connecting the new iMac to my 2015 MacBook and again no success.
Is there anyway I can connect my 2011 iMac (which isn't 4k or 5k) as a second display to my new iMac? If so, with which cables? and what configuration is required to get my new iMac to recognize another display attached?
I'm running Sierra on the new iMac as well as on the MacBook Pro - so OS doesn't seem to be the problem. And I'm running OS X (Capitan) 10.11.6 on my old mid-2011 iMac (the one I'm wanting to use as second display.