Mac Pro Dual Monitor Issue

Discussion in 'Mac Pro' started by mongorama, Sep 23, 2011.

  1. mongorama macrumors newbie

    Feb 13, 2009
    I'm not sure if there's anything I can do about this, but thought I'd ask. I have a Mac Pro (Early 2009) running Lion, with a Radeon 5870, and 2 monitors. Both monitors are connected to the 5870 with HDMI to Mini Displayport convertors (Different brands for the convertors).

    For the most part, I use the secondary monitor for iTunes, iCal, Twitter, etc... Anytime I turn off that monitor, even if for just a minute, then turn it back on, all app windows that were placed over on the secondary monitor get moved back over the primary. It's not a deal breaker, but it's a bit unfun to reposition all of these apps several times a week.

    Is this a common issue?
    If not, is there a silly fix I'm not realizing?
  2. The-Pro macrumors 65816

    Dec 2, 2010
    Maybe try and connect the monitors to different outputs on the cards. Switch them around. I had a similar issue but with two GT 120's it was better when i moved my second card to the third PCI slot. And at one point it was gone.
  3. M&M macrumors regular


    Jan 22, 2008
    Joliette, Quebec, Canada
    Why turn the display off. Just use sleep mode.
    And no it's not a common issue.

    Try using the DVI connectors if you have them and check how the displays behave later.

    Good luck
  4. initialsBB macrumors 6502a

    Oct 18, 2010
    Wirelessly posted (iPhone: Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_5 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8L1 Safari/6533.18.5)

    My 2 screen setup doesn't do that. Once they are plugged in end to end, it doesn't matter wether they are in sleep mode or entirely off. One is mDP-DVI and the other is DVI-DVI. I have a 5770 but I assume that doesn't change from your 5870.

    It seems to me either the adapter or the screen is making OS X think there is only one monitor plugged in.
  5. mongorama thread starter macrumors newbie

    Feb 13, 2009
    I think I've tracked it down to the Moshi HDMI to MDP adapter that monitor was using. I've replaced it with a Kanex brand adapter and it's just fine now.

    Thanks all.

Share This Page