5 Replies Latest reply: Apr 26, 2013 12:58 PM by The hatter
RichardE Level 1 Level 1

I have a Mac Pro (Mid 2012) with AMD HD 5870 card. I currently use two DVI displays which work fine, and I want to add an HDMI display for video work. The first DVI display is connected to the DVI port. The second is connected via a simple adaptor to the adjacent MiniDisplayPort socket. I have a simple MiniDisplayPort to HDMI adaptor for the third screen, but when I plug it into the remaining MDP socket the screen connected to the DVI port goes off and instead its image is displayed on the HDMI screen.


Needless to say, I want all three running. I can imagine the "simple" adaptors I have are insufficient, and that if I had 3 x DVI displays, I would need Dual-Link DVI adaptors for the MDP sockets, but there is no such thing as a Dual-Link HDMI adaptor.


Anyone any ideas?



--Richard E

Mac Pro (Mid 2012), OS X Mountain Lion (10.8.3)
Solved by The hatter on Apr 26, 2013 12:58 PM Solved

Okay.... Solved~ !

Reply by The hatter on Apr 13, 2013 12:51 PM Helpful

Apple Mini DisplayPort adapters: Frequently asked questions (FAQ)


Guide to Apple graphic display adapters needed


Atlona (Dual Link) DVI to Mini DisplayPort Converter for Apple 27-inch LED and 27-inch iMac

http://www.atlona.com/Atlona-Dual-Link-DVI-to-Mini-DisplayPort-Converter-USB-Pow ered.html

Mac Pro (Early 2009), Mac Pro (Mid 2010), Mac Pro (Mid 2012): Issues with three displays and multiple DVI, HDMI connections

It's not the USB data that is needed to run three displays. It's the extra POWER. If you read the Apple article, they say the only solution they endorse is their US$100 Dual-Link adapters. Check the table at the end of the article.

Mac Pro (Early 2009), Mac Pro (Mid 2010): Supported display configurations

Readers here have found that if you have two Brand-X Powered adapters, aka active adapters, it also works fine. These do not always require another USB. If designed recently, they can pick up a power pin in the Mini DisplayPort interface.

AMD (makers of the 5770 and 5870) lists the qualified POWERED adapters that meet their most stringent requirements. Look down the page and you will find several qualified Active Mini DisplyPort to various others, such as HDMI. These adapters are available from other outlets, such as Amazon, sometimes for far less than the Apple adapters.


The other desktop monitor will plug directly into the DVI port on the card and the 40 inch tv will still connect via HDMI over the second Mini Display port.

That will work only if you use an active Mini DisplayPort to HDMI adapter.

The only (someone) have found to work (2009)


but you should confirm that they are really active before buying 500 of them.

You can connect a DVI to HDMI adapter or cable to an active Mini DisplayPort to DVI adapter but that won't give you any audio over HDMI. You could connect the DVI displays to the Mini DisplayPorts with active adapters and use a DVI to HDMI cable or adapter from the DVI port to the TV.

If you want audio via HDMI, you can use audio from the Mac Pro's optical output with this DVI to HDMI converter:



Discussion: Using three ports.


All replies