[djjazzy41]

Originally Posted by johnnyv

Oh, interesting! I'm out of town at the moment, and I don't off the top of my head recall which exact card I'm using. As I recall, it has at least 1 HDMI (although I think it has 2), a DVI and 2 Mini Display ports.

I have a total of 4 monitors working; one for ProTools, two for client monitors in the Control Room and one in the Recording Room for ADR, etc.

Thanks for letting me know about the power "Y" cable. I'll search one out...

I'm using the Sapphire HD 7950 Mac edition video card (it does take two power connectors). It is pushing a full 4K @ 60Hz main monitor from one of the MDP ports with the use of a full 4K MDP-DP adapter. The video card can be found here: https://eshop.macsales.com/item/Sapphire/100352MAC2/

The Y cable for splitting power from my Mac Pro's board to cover both plugs on my video card is this one: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Everything works perfectly; full 4K to the main monitor, no problems feeding the 2nd monitor, and power to the HDX card. As the others have said, hopefully this solves your problem. Just wanted to provide the links to the stuff I used successfully.