Unsolved
2 Posts
0
5280
December 15th, 2020 09:00
P2715Q, Mac Pro, daisy chain not working, mirroring
Hey everyone,
I have two Dell P2715Q's set up to daisy chain with one another. I have a Mac Pro running a MDP to Display A's DP-IN port. Then, I have a DP-OUT cable running from Display A over to Display B's DP-IN port.
The setup works great so far, in that I'm able to see an image on both displays. However, the problem I'm facing is that they're mirroring each other instead of treating it like a separate display. I'm on Mac OSX, and normally, I'd go to System Preferences -> Displays and it would give me an option to deselect Mirroring and set up an arrangement of my displays so I can use them independently. That option is not available in my current Displays setup. I see no Arrangement tab.
Any ideas on what I'm doing wrong in my setup? Does a DP-OUT -> DP-IN connection only support mirroring? I'd love to get these both up and running independently.
Thanks so much for your help!
addfrench
2 Posts
0
December 15th, 2020 11:00
Understood. Thanks for your helpful reply. Sorry for the repeat question.
jphughan
11 Legend
•
14K Posts
•
79.9K Points
0
December 15th, 2020 11:00
@addfrench To build on the answer above, macOS does support Thunderbolt daisy chaining, but that only works with actual Thunderbolt displays, not USB-C/DisplayPort displays. It is also possible to use a Thunderbolt dock or a Thunderbolt 3 to Dual DP adapter to run multiple displays from a single output. But those options might be exclusive to Thunderbolt 3, which use a USB-C connector. You mentioned an mDP output here. Since you didn't specify what generation of Mac Pro you're using, I don't know if that port is just a regular Mini-DisplayPort output or one that supports Thunderbolt 1 or Thunderbolt 2 (both of which used the MiniDP connector style), and again even if it is Thunderbolt, I'm not sure the options I just described would be possible. I just wanted to clarify that answer in case you saw other cases of macOS systems running daisy chains or otherwise running multiple displays from a single connector. Those would be Thunderbolt-based solutions.
jphughan
11 Legend
•
14K Posts
•
79.9K Points
0
December 15th, 2020 11:00
@addfrench This seems to get asked here about once per month. macOS does not support DisplayPort MST, which is required for daisy chaining if you want each display to show unique content. A mirrored image and the system only detecting one display is what you get when you connect a daisy chain setup to a system that doesn't support daisy chaining. Ironically if you were to run Windows on your system through Boot Camp, the daisy chain would work fine. It's just an OS limitation that's existed for years, and has been the subject of complaints on Apple's forums, here, and elsewhere on the Internet for years.