Dual Thunderbolt = Dual Displays?

Question

Level 1

10 points

Dual Thunderbolt = Dual Displays?

I have been using multiple projector setups for a while. I engage in lots of "projection mapping". I would consider myself well versed in the Mac world but his one is stumping me...

I have a Mac Mini (brand new) and a 2014 Mac Book Pro Retina. Each has two thunderbolts. I am assuming I can run two, independent, monitors/projectors from these - one in each port. Right? I have been trying this without any success...

I tried new cables, new adapters, switching ports, different computers (both projectors works just fine of course). However, I was never able to get both projectors working at the same time. All I get in one monitor/projector populated in System Preferences -> Displays.

The second projector never populates in System Preferences -> Displays. It never registers a source. My projectors are fine. I have even tried this with HDMI monitors. Why is this happening? Is it fundamentally correct to assume that a dual thunderbolt setup can drive dual, separate, displays?

MacBook Pro (Retina, 15-inch, Late 2013), OS X Yosemite (10.10.3)

Posted on Aug 16, 2015 7:14 PM

Reply

Answer 1

Lanny

Level 6

13,183 points

Aug 17, 2015 7:15 AM in response to Casey 5ense

Is it fundamentally correct to assume that a dual thunderbolt setup can drive dual, separate, displays?

No, not knowing the specifics, i.e., the resolutions used for each, doesn't help.

But, do recognize that the MacBook Pro's (once again, specifics not given, top end 15" MacBook Pros have even higher graphics performance) have much higher graphics capabilities than a MacMini.

Reply

Answer 2

Casey 5ense Author

Level 1

10 points

Aug 17, 2015 7:53 PM in response to Lanny

Thanks for the reply Lanny,

I would imagine it should work with many different resolutions. Indeed the combinations I tried before posting here were of many different resolutions - none were able to breakthrough.

However, to provide a basis for discussion, lets say each projector is "1024 x 768" using a "VGA Cable" and a "VGA to Thunderbolt Adapter" on a "2014 MacBook Pro Retina (top of the line)". This combination is indeed what I have but I would imagine it should work with many other Mac computers provided there are two Thunderbolt ports and the resolutions are of reasonable size.

That being said, has anyone used x2 Thunderbolt ports to drive x2 independent monitors (regardless of resolutions/configuration)? I am really interested in knowing how it should show up and how to get my computer(s) to seamlessly recognize x2 monitors/projectors.

Thank you for any tips,

Reply

Answer 3

lllaass

Level 10

210,411 points

Aug 18, 2015 1:27 AM in response to Casey 5ense

Yes, each Thunderbolt port can drive one monitor . For two monitors the resolution is limited to

Video Support

Support for up to two displays at 2560 by 1600 pixels, both at millions of colors

One Thunderbolt port, like the HDMI port can do:

Support for 3840-by-2160 resolution at 30Hz
Support for 4096-by-2160 resolution at 24Hz
The resolution of the monitors can be greater than 2560 by 1600 but will be down scaled. to tha or less depending upon the aspect ratio. That sometimes results in a less than optimum viewing experience.

Reply

Answer 4

Casey 5ense Author

Level 1

10 points

Aug 18, 2015 10:46 AM in response to lllaass

Thanks lllaass!

Where did you find this information?

I aim to take full advantage of the specifications you listed. I plan to use a Matrox Triple-Head-2-Go DP Edition on each Thunderbolt for a total of x6 projectors. But... Let's dial in the simple version first...

Why might this not be working on my machines? Am I literally hooking them up wrong? I'm contemplating makign a YouTube video to show how I plug them in and illustrate the connection problem. I know this can work and am eager to find out what I am doing wrong.

Is this a common problem?

Reply

Answer 5

lllaass

Level 10

210,411 points

Aug 18, 2015 10:55 AM in response to Casey 5ense

What specific monitors or projectors have you tried?

What is their native resolution?

What input on them are yo using?

Is the HDMI port disconnected?

Reply

Answer 6

Casey 5ense Author

Level 1

10 points

Aug 18, 2015 11:20 AM in response to lllaass

I have used a lot of Epson Projectors.

The 1960 Powerlite at 1024 x 768

The X15 Powerlite at 1024 x 768

All using VGA. Nothing in the HDMI port.

Reply

Answer 7

Mar 22, 2016 9:34 AM in response to Casey 5ense

I realize this is quite old, but...just wondering if you were able to pull off the dual TripleHead2Go from both thunderbolt ports of a 2015 macbook pro (w/ AMD additional video). I'm looking to try a similar thing to drive 4-5 projectors (HDMI) total. Any info would be greatly appreciated!

Reply