Mac Pro 2008 Target Display Mode iMac 2013

[christiann]

Hi there,

I have a Mac Pro 3,1 with an RX 560. The ports on the RX 560 are DP, DVI, and HDMI. I know my Late 2013 iMac (3.1GHz i7, 16GB RAM, 1TB, 21.5”) supports Target Display Mode. By change could I use a DP to mini DP cable or HDMI to mini DP to use my 2013 iMac as a display for my Mac Pro? Both run macOS Catalina.

 

[joevt]

Late 2013 iMac supports Thunderbolt Target Display Mode, not DisplayPort Target Display Mode, so it will not support Target Display Mode from a Mac that doesn't have working Thunderbolt.

You can add Thunderbolt to MacPro3,1, but I don't know if anyone has been able to make it work well enough to support Thunderbolt Target Display Mode. First, the MacPro3,1 needs to see the iMac connected as a Thunderbolt device in the Thunderbolt tab of System Information.app. If the MacPro3,1 can see a Thunderbolt device in the Thunderbolt tab of System Information.app, then it probably means it can see a Thunderbolt Mac.

Maybe look at this thread https://forums.macrumors.com/threads/testing-tb3-aic-with-mp-5-1.2143042
I have not tried using an SSDT (I have OpenCore/OCLP so I could try that) or flashing the firmware of my Thunderbolt Add-In cards.