Gigabyte RX 460 (4GB) + Mac Pro 5.1: only HDMI-out works

Discussion in 'Mac Pro' started by StefanJohansson, Jun 27, 2017.

  1. StefanJohansson, Jun 27, 2017
    Last edited: Jun 27, 2017

    StefanJohansson macrumors newbie

    StefanJohansson

    Joined:
    Jun 27, 2017
    #1
    I got a Mac Pro 4.1, and have flashed it to 5.1

    Replaced the original graphics card (GT120) with a Gigabyte RX 460 (4 GB version, https://www.proshop.se/Grafikkort/Gigabyte-Radeon-RX-460-OC-WF-4GB/2562561)

    I simply cannot get the DP to get working, tried two cables to my Dell U2515H (DP-DP and DP-mDP) but the monitor says it gets no signal. However, the HDMI signal (HDMI-HDMI) works just fine.

    Any idea why this happens?
    Do I need to edit something in my settings?

    I tried to enable/disable DP 1.2 on the monitor without success.

    Runs the latest OS X 10.12.5
     
  2. Kris Kelvin macrumors member

    Joined:
    Dec 28, 2005
    #2
    I've tested the same card in my Mac Pro 2009 (flashed to MacPro5,1) and it worked flawlessly with an LG 34UM95-P over DisplayPort.

    Does the display show up in System Profiler when connected with DisplayPort?
     
  3. OEMPT macrumors newbie

    Joined:
    Nov 9, 2015
    #3
    You probobly have your monitor setup wrong. You MUST disable DP 1.2.

    I use the exact same card with 3 Dell U2515H monitors, 1 dp + 1 hdmi + 1 dvi. The moment I would turn on DP 1.2, I would get a blank screen and have to do a workaround to disable it. Sierra does not support "daisy chaining" which requires the DP 1.2 protocol, maybe only with High Sierra but that's to early now to confirm until later releases come out.
     
  4. StefanJohansson thread starter macrumors newbie

    StefanJohansson

    Joined:
    Jun 27, 2017
    #4
    Thanks for replies!

    @OEMPT - will disable DP and restart everything and see if it works. Are you also running OS X 10.12.5?

    @Kris Kelvin - cannot check that as I have a black screen when DP-connected :)
     
  5. Kris Kelvin macrumors member

    Joined:
    Dec 28, 2005
    #5
    Well, you could connect both HDMI and DisplayPort at the same time – or use Remote Desktop if you have a second computer. Where there's a will there's a way. ;)
     
  6. StefanJohansson thread starter macrumors newbie

    StefanJohansson

    Joined:
    Jun 27, 2017
  7. Kris Kelvin macrumors member

    Joined:
    Dec 28, 2005
    #7
    Either that or launch the app "System Information" (found in /Applications/Utilities), and take a look at the entry Hardware -> Graphics/Displays.
     
  8. StefanJohansson thread starter macrumors newbie

    StefanJohansson

    Joined:
    Jun 27, 2017
    #8
    With DP 1.2 disabled and a restart, the GPU works like a charm :)
    Thanks a ton for your help!

    @OEMPT Now I will buy a 2nd Dell U2515H monitor (or even two more :) )
     
  9. joebclash macrumors regular

    Joined:
    Jun 14, 2016
  10. StefanJohansson thread starter macrumors newbie

    StefanJohansson

    Joined:
    Jun 27, 2017
    #10
    I disabled it on my monitor (Dell U2515H), in the monitor menu, i.e. not in Sierra.
     
  11. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #11
    Well, I'm confused. It didn't work the first time you disabled DP 1.2, but it did the second time?
     
  12. StefanJohansson thread starter macrumors newbie

    StefanJohansson

    Joined:
    Jun 27, 2017
    #12
    For some reason yes... I don't know exactly how/why. Maybe the cable was not fully plugged in the first time. Anyway, now HDMI-HDMI, DP-mDP and DP-DP works perfect, so I am a happy owner of a RX 460-card :)
     
  13. RexyStef macrumors newbie

    RexyStef

    Joined:
    Apr 4, 2017
    #13
    What's the link speed you get with the rx 460? in the OpenCL ocean waves and bandwidth benchmark I only get 1.50gb/s. also, do you see it under system profiler pic section or do u get the error also?
     
  14. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #14
    Ocean waves is not consistence, simply close it and open again may show a significant different number.
     

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