3 Monitors on MacPro and ATI Radeon HD5770 (VGA)

Discussion in 'Mac Pro' started by frankyboy, Jan 19, 2013.

  1. frankyboy macrumors newbie

    Jan 16, 2009
    Current Setup: MacPro 5.1 (2010) with Logic 9 and ATI Radeon HD 5770 and 3x 24" Monitor (2 with DVI & VGA, 1 with VGA only)

    does someone know if one or both of the following setups will work with 3 monitors?

    1. Setup:
    ATI DVI -> Monitor1 DVI (Single-Link)
    ATI MiniDisplayPort - DVI Adpater -> Monitor2 DVI (Single-Link)
    ATI MiniDisplayPort - VGA Adpater -> Monitor3 VGA

    2. Setup:
    ATI DVI - Monitor1 DVI (Single-Link)
    ATI MiniDisplayPort - VGA Adpater -> Monitor2 VGA
    ATI MiniDisplayPort - VGA Adpater -> Monitor3 VGA

    could setup 1 be working, if only 1 adapter is active but VGA and not DVI.

    i know to use 3 Monitors on a ATI Radeon HD 5770, Adapters must be active, such as the expensive Apple MiniDisplayPort - Dual Link DVI Adapter, which i don't want to buy and use.
    MiniDisplayPort - VGA Adapters are active too. that's why i'm asking about those 2 setups above. to make sure, if one or both would work, so i can purchase 1 or 2 MiniDisplayPort - VGA adapter.

    thanks for any help in advance.
  2. rezwits macrumors 6502a


    Jul 10, 2007
    Las Vegas
    I am trying to do pretty much the same thing but

    I have read that you need to have Active Adapters like you have said in your post but I am thinking of trying:

    Two of these -

    and then a regular old DVI to HDMI cable on the DVI output.

    I have two regular MDP to HDMI adapters but I wonder what makes these "Active" is there a battery or something in the bigger little case? :p


    But assuming I go this route does anyone think this will work?

    I am pretty sure your method will with VGA from what I read.

    I just don't see what is so special with the above adapter, and why they would make passive instead of active in the first place...

  3. pcmxa macrumors regular


    Apr 9, 2011
    Setup1 will not work. I have tried it and it doesn't. Setup 2 will. It is what I am running now.
  4. frankyboy thread starter macrumors newbie

    Jan 16, 2009
    great news, thanks so much for your help. i really appreciate it very much.
  5. strikingtwice macrumors newbie

    Mar 28, 2007
    similar question

    Hey guys, I know this thread is a few months old, but I was wondering if it got resolved for the OP.

    I have a 2009 right now with the 5770. The vga monitor i have just isn't working. My dell through the dvi is fine, and although the VGA monitor appears to know it's connected (i actually have the apple mdp to vga right now) but it doesn't show up in sys profiler or anything.

    Any suggestions?
  6. sarthak macrumors 6502

    Nov 19, 2012
    Try using this:

    That way it may act as if it is connected like a DVI monitor.
  7. The-Pro macrumors 65816

    Dec 2, 2010
    Im using a HD 5770 in a 2009 8core Mac Pro and I have 3 displays attached.
    30" ACD over the DVI connection on the 5770.
    Then 2 x 23" Acer screens each connected with an Apple MDP - VGA Adapter.
    Works perfectly
  8. nwind, Aug 18, 2013
    Last edited: Aug 18, 2013

    nwind macrumors newbie

    Aug 18, 2013
    3 monitors with display port and DVI


    I have late 2009 MP and two monitors with both DVI & display port (NEC PA301W & NEC PA271W) and they where working fine.
    I need a third one and was trying to connect an old 20" HP LP2065 (2xDVI 1600x1200) but no success. It was connected to DVI port.
    System is kind of detect it (I can see 3 monitors in display settings) and unit stay active (signal is going through the cable) but screen is black.
    According to Apple note this config should be perfectly supported:

    HP unit is fine since it works fine on my MBP.

    Eventually I connected it with installation of second old stock NVIDIA card but don't like this setup.

    Is anybody have some suggestions?

  9. nwind macrumors newbie

    Aug 18, 2013
    To clarify:

    Both NEC displays has ability to be connected either through DVI or display port.

    Actual not properly working config:

    2 x NEC connected directly through display port to 5770.
    HP connected directly through DVI to 5770.
    All passive connections.

    Actual working config:

    2 x NEC connected directly through display port to 5770.
    HP connected directly through DVI (or display port to DVI Apple adapter) to stock NVIDIA card.
    All passive connections.

    It's not working even with only HP connected to DVI and nothing else.
    Not working is funny. With all 3 connected as I mention I can see 3rd monitor in display settings and it's detectable (keep it awaked as well) but with completely black screen. Maybe signal from 5770 is just marginal for HP display?
    Cable and monitor are OK since they are working on the second card and my MBP through adapter.

    BTW according to Apple with straight connection to all 3 ports (no conversion) it must be perfectly functional with all passive connections.

    See the first line on they table:



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