Mac Pro with 3 display setup problems

Discussion in 'Mac Pro' started by tdg911, Dec 5, 2011.

  1. tdg911 macrumors newbie

    Dec 5, 2011
    I have an early 2008 model Mac Pro running Lion 10.7.2. 16G ram and dual quad core processors. The workstation runs quite beautifully. I recently sold my 30" cinema display to go with 3 23" led samsung displays. I am using a ATI Radeon HD 5770 video card. The monitors are all Samsung SA550 monitors running 1080p resolution.

    Two monitors are using the mini display port to dual-link dvi adapters and one display using dvi connection.

    All is good up to this point. This setup actually works quite nicely and is a lot cheaper than going with the 30" imo.

    Here's the problem: Whenever the displays turn off while the system is inactive sometimes the display will not come back on unless turning the power OFF and on the monitors (leaving the other two off until the main comes up) or the monitors kind of alternate as if the system does not know which monitor is the main! This will stay like this if I do not turn all monitors off except the main. Once the main comes back on I then turn on the other two.

    This is beginning to be quite annoying.

    Has anyone experienced this issue and have some kind of a fix? I've read where some people are having similar issues when connecting external monitors to their laptops but I haven't seen any fixes for those scenarios.

    Thanks in advance,

  2. Varmann macrumors member

    Jan 3, 2010
    I have a similar setup and experience somewhat similar problems. But I have no solution so far.

    First setup: 2008 model 16GB, 2x2.8, Lion 10.7.2, ATI 5770
    3 Displays: Dell 30" (displayport), Sony 23" (DVI), Optima projector 1080 (Displayport->HDMI) (I arranged the display desktops in that order as well)

    I usually only have the two normal displays on, with the projector in standby.
    I also normally put all displays in standby when I leave the house or go to sleep. When I turned them on again the arrangement of the displays were changed. Every time.

    I tried to fix it by putting in other card as well, my old original ATI 2600, and connect the projector to that card (DVI -> HDMI). It improved things a little. Now the desktops are not re-arranged during sleep, only the open windows on the desktops. When I turn on the displays I have to collect a couple of open windows that has been moved to the "projector-desktop" (usually not visible since I rarely turn it on, except for watching movies). A bit frustrating....
  3. VanneDC macrumors 6502a


    Jun 5, 2010
    Dubai, UAE
    s'funny when you say ati 5770, do you mean an apple 5770 or a pc flashed one? might wanna clarify that in your posts. :)
  4. Varmann macrumors member

    Jan 3, 2010
  5. sparkie7 macrumors 68010


    Oct 17, 2008
    I have a Mac Pro 3,1 as well - 2.8GHz, 8 core, 16GB RAM, 1x ATI HD 3870, 1x Apple ATI HD 4870, running 3x 30" ACD's -- one off the 3870, the other two off the 4870, one using a MDP dual link DVI adapter. Sometime I get a little flicker from one of them but generally they all run smoothly.

    Maybe check if you need to update the firmware/drivers on your graphics cards?
  6. Varmann macrumors member

    Jan 3, 2010
    After a few days in frustration with this new setup. Found out something that at least fixed my problems. I changed the displayport I connect my main screen to on the Apple 5770 (to the one at the bottom). Now The open windows behave as expected when turning on the displays. Guess the two DP-ports on the card are far from equal.

    At least my problem seem to have an easy solution. :)
  7. sparkie7 macrumors 68010


    Oct 17, 2008
    I remember the first MDP dual link DVI adapter I bought from the store was flakey. It caused flickers and weird artifacts on an inconsistent basis. Finally figured it was the cause as others had reported the same issue. I went back to the store and swapped it out for one that works without glitches :D

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