How do I connect a 3rd 4K monitor to my 2013 Mac Pro? I have a Mac Pro 2013. I already have two 4k monitors now connected to

the HDMI port (Bus 0)
a thunderbolt port with a TB->HDMI adapter (Bus 1)
Before I simply buy a third monitor and adapter, is it as easy as that?

Do I just plug another adapter into the last BUS that isn't being used? (I understand to separate the monitors on different buses.)

FYI, I tried a 3rd monitor that wasn't 4k and it didn't fire up/get recognized. I read somewhere on Apple's site that once you have one 4K monitor connected you need all of them to be 4K.
The main article on 4k displays links to the below article on Mac Pro:


https://support.apple.com/en-us/HT206587
https://support.apple.com/en-us/HT202801


The trick for the third display on Mac Pro is to use 2 Thunderbolt and one HDMI cable to connect each directly to the Mac Pro. Basically each bus can handle 2 normal displays or one 4K display each.


  Three 4K displays: two connected via Mini DisplayPort and one connected via HDMI


You are correct about bus 0 conflicting with the HDMI adapter as well.



If you're not on the 2013 Mac Pro - see this thread for options for "unsupported" adapters that might work for lower resolutions or lower refresh rates than the native ones.

How can I run 3 4K monitors on my 2015 MBP