Mini Display to HDMI

Question

Mini Display to HDMI

I am having difficulties connecting 4 displays to my Mac (late 2013 "trashcan" model.

I am attempting to use 3 projectors and a standard monitor display (this is a live theater project). I have two computers for this project, and one is working fine and recognizing 4 total displays (three projectors which are all connected via Mini Display converted to HDMI). The functional computer is the main system used for the performance.

The other, problematic, computer is supposed to be used as a backup system. When connecting all of the displays, this Mac only recognizes 3 out of the 4. No amount of repacking or cable swapping has resolved the issue so far.

Does anyone here have any suggestions?

Mac Pro

Posted on Feb 28, 2023 3:30 PM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

140,261 points

Mar 1, 2023 5:47 AM in response to BrettWhelan03

First, does each display work when it is the only display?

Legacy Interfaces (anything other than DisplayPort or its incarnation inside Thunderbolt or USB-C) use higher voltage levels than DisplayPort. Graphics cards (including the ones inside Mac Pro) can not provide enough power at the higher Voltages to run more than TWO legacy displays reliably.

The solution is to use more adapters sold as ACTIVE (and slightly more expensive). These contain additional Driver circuits that can power a display without using up the graphics card's ability to power its interfaces.

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Answer 2

Mar 1, 2023 6:53 AM in response to Grant Bennet-Alder

Grant-

First off thank you for your detailed response. Your diagnosis of the issue is spot on.

Our main show computer has three identical active adapters that are supplying sufficient power for three displays at 1080/60hz.

Our backup (problematic) computer is using three separate dongle adaptors that do not have sufficient powering capabilities for 3 displays.

Thank you again for your insight and I hope this exchange can help someone else in the future!

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Answer 3

Mar 1, 2023 8:51 AM in response to BrettWhelan03

If you have three that work and three that don't you may be able to do some immediate swapping around to get almost all working.

Long term for 'show' computers, you may want all ACTIVE to avoid ANY issues at show-time.

One more footnote I left out:

If you choose to use the built-in HDMI port, that counts as one out of your allotment.

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Mini Display to HDMI

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