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Mac Pro 2013 Multiple Displays Stop Working with OS X 10.9.3 – Fixed

Hot to Fix Multiple Monitors not working in OS X 10.9.3 OS X 10.9.3 Mltiple Monitor Problems

Mac Pro 2013 computer users have experienced problems in some configurations since upgrading to Mavericks OS X 10.9.3. For most people, the issue related to the use of mini port to DVI external monitors.

The mac pro by design can only run two Miniport to DVI monitors, and any additional monitors need to be run on a converter that has additional power. Apple call this their Dual Link DVI adapter. Essentially this is the same thing, just with a powered USB port on it. If you were to try an run 3 mini port to DVI adapters, what you would find is that only two monitors plugged in would run. Effectively the last two plugged in in any combination would be the two that ran.

Apparently this is by design, and part of the way that the Mac Pro is set to provide a stable and powerful signal in the miniprot to DVI adapters. The additional power that is required is subsequently provided by the Dual Link (USB port).

The problems OS X 10.9.3

With this update, only two monitors would work, were previously more would run fine. Many online communities were talking about this problems that is considered serious for IT professionals. Here at we identified the problem, and lodged a support ticket with Apple. We had some back and forth providing the photo’s of our configurations, and some software tools that they provided to give system feedback.

The Fix for Multiple Display Problems OS X 10.9.3 – is 10.9.4

Today we received a final version of OS X 10.9.4, and to our joy it has restored the monitor problems that we experienced and things are back and firing as they should.


I have seen some people digging in for a sledging of Apple over this issue. Personally I am old enough to have experienced this type of serious issue with other more prevalent operating system. In those instances, the disconnect between manufacturer, OS developers and software developers meant that we sometimes never fixed display problems. I can remember one instance with a Matrox graphic card that we paid something like $1200 for, and never could get it working as designed due to operating system changes and software incompatibilities. We later found the same cards on sale for $50 after we had dropped $6 K into the cards. 

It was problems like that that, and the fact that no matter who we told our problems to (MS, Matrox, or 3rd party software developers) that we could never get a fix. No one would own the problem. That is exactly the reason we changed to “Apple Fan Boys” and although we have spent 10 days with less than optimal Mac Pro systems, it still remains that we had a problem. Told Apple, and they fixed the darn thing in a timely manner. Well done I say!


37 thoughts on “Mac Pro 2013 Multiple Displays Stop Working with OS X 10.9.3 – Fixed”

    1. I have access because I am in their developer program. I would expect the release next week if testing goes well as Apple has it’s WWDC and often release updates to support new hardware. A few more days…

  1. I am so frustrated with the system that I am beginning to think that the fix for 10.9.x issues is Windows.

    1. Hardly.Like drilling a hole in your head to let the leaky stuff run out! I suspect that an update will be released in 24 hours with the WWDC 2014 about to start. They usually do this. Stay tuned!

  2. We had the same issue with a $12000 set up stopped running a 3rd display. After a day on the phone the result was “wait for the next OS update some time in the future..”
    and “You should have done a time machine backup before you upgrade.”
    Very frustrated because we are using this mac professionally.
    Turns out the reason I did not have a backup was that time machine stopped working with our apple server via network as I had it set up. (Apple does not support that any more…).
    I would like to see a WARNING before installing an upgrade that functions of the OS might disappear and I should make sure to have a backup BEFORE hitting the ok button.

  3. I also have been struggling with this issue. Thank goodness you posted this, to clear this issue up. It was really hard pinning down someone at Apple that knows about this issue. I hope 10.9.4 comes out soon. There are other issues related to 10.9.3 that seemed to have broken applications access to GPU usage, such as Adobe Premiere Pro CC and Adobe Media Encoder and Davinci Resolve 10…all reporting issues with things like playback, rendering, and everything in between….

    1. Glad to help. They released another pre-release version of the next update today. It is more stable in a few areas, so hopefully they are getting close to a public release.

  4. I have also noticed an issue with 10.9.3 which affects the GPU particularly. I am running Premiere Pro CC and the GPU is definitely struggling to handle basic projects which is so frustrating! I am getting a lot of stability issues with the app crashing regularly and often the entire machine freezing up. No sign of 10.9.4 yet so I hope it comes soon because I am struggling to work on this system as it is which is crazy given the amount of money invested into it. By the way, I am running 3 x 27inch HP monitors via Display Port to Mini Display port ensuring that they connect to a separate bus on the MacPro and this seems to work okay for me. Not sure if it is the same for DVI users.

  5. Philip Galaura

    I have a 6 core Mac Pro 6,1,The issue I’m having with 10.9.3 is that I have an HDMI 42″ display connected works fine, if I try to add a minport to DVI display, it disables the HDMI, end result is I can only have one connected. Very strange. Thank you for all the info.

  6. Thank you.
    I had the exact same issue; only two of my four monitors would work with 10.9.3 on my new «black cylinder.» Had to downgrade to 10.9.2.
    I followed your advice and 10.9.4 seems to work just fine.

    1. It’s a pleasure.
      Another issue I have come up with is that the Time Machine restore will not work with multiple monitors enabled. The solution is to temporarily set the displays to “mirror” before jumping into the time machine. Then remove that setting once you have finished. All the displays will jump back to normal after that.

  7. there is still an issue. Im running 10.9.4 and from 3 monitors connected like 2xmini DP/thunderbolt and DVI-D as a HDMI-DVI converter only 2 of them work in all combination i tested ;/.

    1. Is one of them a powered link device. They call it a dual-link display adapter. You need one of the three display links to be using the dual-link. The pro only has the power to display 2 displays without the assisted poser in from another USB power device. This is what the dual-link is designed to do.

    1. Actually not for me. I found that the second monitor dropped out initially. I then rebooted and all is fine. Try a reboot and or unplugging the monitors and putting the back in a different order. In short, I have the same physical setup and 3 monitors working fine in Yosemite.

      1. Hi,
        I have exactly the same issue.
        Yosemite installed on a non supported MacPro…
        Found a “hack” for Mavericks 10.9.3 but then again under Yosemite, only 2 screens over 3…
        Still both CG (GT610) are recognized but only one cards working.

  8. under 10.9.3, there was a trick posted on the net that suggested to use the drivers from 10.9.2 and if i remember well a command line… but i never could find it again somewhere… as i was afraid it wouldn’t work on the next updates, i kept on 10.9.3 and jumped into yosemite…
    then the story started again!

  9. i have a 2560*1440 display (latest asus rog with g-sync) that has only DP input, worked fine in ML, didn’t work on mavericks, even in 10.9.5. when plugged in nothing happens and osx nearly freezes, once i disconnect the displayport, back to normal.
    i’ve solved with nvidia drivers for mavericks from nvidia website (331 if i’m not wrong). Fortunately i did the update only yesterday, cause this issue was solved basically in september, so many months without solutions!!

    1. Yes, things are a little flaky for me still. Every time I restart the computer I need to remove then re-attach one of the monitors to get it to be seen by the system. Not really a solution, but I think I will just update to 4k monitors and be done with this.

  10. Im having an issue i have 2 Mini DisplayPort (Thunderbolt) to HDMI Adapter for 3 Hdmi TV’s on my Mac Pro Late 2013 and i have a one Hdmi from one tv straight to the computer but only 2 display any suggestions ? Running OS X Yosemite 10.10.4

  11. I have the same problem j.d. Just got off the phone with apple support after 2 hours they want me to call back tomorrow. Mac Pro 6 core with quad 32″ insignia tvs and will only display 2 at any one time. Hdmi port and port 4 were working then all of a sudden hdmi port stopped working and port 1 worked but never more than 2 monitors working. If anybody has any ideas it would be much appreciated. Otherwise I foresee many hours on the phone with support. Thanks

  12. I also have a Macbook Pro running 10.10.5. For a few versions of Yosemite my additional 3 monitors worked fine. Now I can only use one
    I have a 2nd Macbook Pro 10.11 (updating it now to 10.11.5) It also will only run one monitor of the 3.
    And yes – I have used different monitors across each.
    Any ideas?

  13. Running MacPro Late 2013 model with two Samsung 32″ monitors and 3rd 720p LG TV display, but only 2 of the 3 work at any time. Whether I use 3 Thunderbolt to HDMI converters or just 2 & the HDMI port itself, the result is the same. I have resorted to a broadcast HDMI Distribution Amplifier, but it has not solved the issue – although it registers both the input signal and two connect displays to send the source signal to, neither of the additional 2 screens show anything. I would understand if this were related to the Thunderbolt bus power issues being limited to only 2 as per the above, but I don’t understand why the HDMI port will not work itself in conjunction with 2 Thunderbolts, let alone why a one of the 2 Thunderbolt ports will not display if the signal is duplicated off board by the DA. Any ideas?

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