For example, I’m running a 2013 Mac Pro at work with a SanLink 10Gig adapter, BMD UltraStudio Express, and a CalDigit dock all connected as TB2. Monitor 1 is a 27″ Mac display connected to one of the Mac’s TB2 ports via its MiniDisplayPort plug. Monitor 2 is an older 20″ Mac display also connected to the Mac’s TB2 ports. There’s a Promise RAID connected to the CalDigit dock’s TB2 and a large Panasonic display connected via HDMI from the dock.
All 3 displays show up in Premiere with video playback going to the Panasonic via the dock. When I had tried to run all of these from the Mac, I couldn’t get 3 monitors to display, because the HDMI from the Mac robbed the TB2 ports of power. So sometimes it’s a bit tricky getting the right combo to work.
Have you tried HDMI on the 3rd display?
– Oliver
Oliver Peters – oliverpeters.com