DELL P2715Q + ATI 7950 picture problems (Macpro 5.1)

Discussion in 'Mac Pro' started by drnoodle, May 8, 2015.

  1. drnoodle macrumors newbie

    May 8, 2015
    Hi guys,

    i got a weird problem on my original MacPro 2012 5.1. I bought a new gfx card to have more power in Davinci, an AMD Radeon 7950 with 6GB Vram. Ive had two Apple 23" HD displays, works great.

    Now i needed UHD displays and decided to buy 2x DELL P2715Q. Bought 2x miniDisplayport - Displayport cable for UHD monitors. Now theres a problem:

    •*First DELL is working with 3840x2160 @ 60hz
    • Second DELL is working with 3200x2160 @ 60 hz

    And both monitors got a 2cm strip grafic fail ! I tested different cabels, also the original ones. I plugged a DELL into my MacbookPro Retina, no fail.

    So i think its a failure of the GFX card, right? But... why? Its no Mac certified card, but that should work though.

    • Macpro 5.1
    • 12 core
    •*AMD 7XXX 6GB
    •*OSX 10.9.5

    [​IMG] [​IMG] [​IMG]
  2. Arron Rouse macrumors regular

    Apr 28, 2010
    Chichester, UK
    I had all kinds of problems with the Mac Edition 7950 and a single P2715Q so it's probably not the PC VBIOS.

    There was a big difference for me switching up to the latest version of OSX - it fixed a lot of problems in the 7950 drivers. It also seemed to introduce a profile for the P2715Q. If you can, upgrade.

    However, before you upgrade, you might want to delete (after taking a backup, obviously) both of your windowserver.plist files and restart to let them rebuild. That fixed a lot of problems for me.
  3. VirtualRain, May 8, 2015
    Last edited: May 8, 2015

    VirtualRain macrumors 603


    Aug 1, 2008
    Vancouver, BC
    4K is bleeding edge that many would say just became usable with 10.10.3. I wouldn't expect great results from that combo. So far, every point release of OS X has brought 4K improvements. Why are you still on 10.9.5?
  4. drnoodle thread starter macrumors newbie

    May 8, 2015
    Ok, thx so far! I am at 10.9.5 because i use external hardware for sound recording RME Fireface 800 and others. Its bad i cant use expensive hardware running good, only because i want to update an OS.
  5. Pending macrumors regular

    Oct 1, 2014
    Doesn't the latest RME Fireface 800 driver just released in April support Yosemite?
  6. drnoodle thread starter macrumors newbie

    May 8, 2015
    Thx guys... update to 10.10.3 works perfect. No error anymore! Also the older RME driver worked though. But the new one is way better.

    Very good!

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