GTX980 3 monitors - weirdness

Discussion in 'Mac Pro' started by stupidassdrumer, Aug 24, 2017.

  1. stupidassdrumer macrumors newbie

    Aug 20, 2010
    Hey all - I have a weird issue getting 3 monitors to work on my tower.

    I have 2 Dell P2715Q 4k monitors that I run as my main monitors, running at 1440p HiDPI each. Both are plugged in using DP to DP cables and I have very little issue with them other than occasionaly one of them doesn't wake from sleep.

    My problem is when I decided to plugged in my old Dell U2410 as a third monitor, so I could run the video window in ProTools, and get extra realestate for my mixing windows (I do mixing for TV and Web series, from home).

    I originally plugged it in via HDMI>HDMI to my GTX980(Non-Flashed). It booted right up and I had a great mixing session moving the video window to this third monitor. I put the tower to sleep that night and upon trying to wake the computer, the tower's light went on, but none of the monitors turned on. I then did a hard reset and the 2x 27" 4k monitors turned back on just fine upon bootup, but the U2410 did not. I turned it off and even unplugged/plugged in the power cord. The 4k monitors blink like they detect that another display is turned on, but then the U24's screen says no connection detected. It's just strange that it worked beautifully that one time, but then doesn't any time after. It detects a signal as the monitors all flash, but then the U24's screen says no signal detected.

    Thinking maybe it's an issue with HDMI, I ordered another DP>DP cable (the same one I use for my 4k monitors), but that had the same issue. It worked the first time I plugged it in, but then as soon as the computer was shut down, it always detects the third display with a flash, but then the U24 displays no signal again.

    I'm stumped why it would work the first time on each new cable, but then never work again. I've tried different combos of Unplugging/Plugging back in the power cord to the U24 and the HDMI/DP cables on the monitors end and the GTX980s end.

    Any Ideas? Thanks!

    MacPro specs: 2010 - 5,1 - (2x)x5690 - 32gb OWC ram - GTX 980 SC ACX 2.0 - 500gb EVO for boot - (2x) 840pro 256gb on a Sonnet SSD raid card, sabrent 4 port usb 3.0 card.
  2. JMVB macrumors member


    May 16, 2016
    I have not 4k monitors, just 1x Cinema display 23 and 2x LG iPS 22, and all work perfect
    Geforce gtx980 4gb

  3. AidenShaw macrumors P6


    Feb 8, 2003
    The Peninsula
    I have a couple of dozen of these monitors - and also see that occasionally (from both Windows and Apple OSX, from laptops and workstations,...

    Sometimes toggling the power switch works, sometimes you need to pull the power cord for a few seconds.

    Otherwise they're great monitors, and worth the rare need to reset.
  4. mikas macrumors regular


    Sep 14, 2017
    As from yesterday I have tested this P2715Q monitor. I really like it. But it did not wake from sleep this morning. Needed to pull the power plug to wake it.

    This behavior could become annoying after some time, because it messes up my other monitors with all these programs open. And what about if it will not wake at all some day.

    Has anybody found any better resolution to this problem but to unplug the power cord. All I can think of is a switch in my extension cord or power strip, so I don't have to do any complicated yoga moves every morning to access the back of the monitor.

    It's a hard decision now, to keep this or not. Need to decide it today.
  5. mikas macrumors regular


    Sep 14, 2017
    About the Dell; Just came home and swapped HDMI to DP. At cold boot it did not come along, no picture at all. Power button is not working. Changed to other DP port - no go. CHanged the signal to mini-DP, and finally it worked.

    Again, I do like the picture quality, but the wake-up problem might make me return this. It's not just that I have to sometimes unplug and plug in the power cord. It just that this procedure makes my desktop a mess. When one monitor is lost, all windows jump to other monitors so that they remain accessible by user. All windows end up in clutter, and with strange sizes too. And I do have a lot of windows and programs open all the time.

    So sad. How can I go back to WQHD, I don't know. WQHD is not a total crap, it's quite good I have to say. But I certainly won't forget the Dell quality of 4K in a day or two.

    Visited the seller shop, and repsesentative kindly gave me more time. I've got couple of days more to change my mind and take it back for a full refund. Or to not take it back.
  6. mikas macrumors regular


    Sep 14, 2017
    HP Z400, RX 460 2GB, Dell P2715Q. Working good, no wake-up problems yet.
    Mac Pro, RX 570 4GB, Dell P2715Q. Working good, but does not wake up from sleep, not from it's own power saving mode, until powered down with power button. And does not wake up from system sleep, until power cord plugged off and plugged in. Sometimes it wakes with power button clickery though.

    You make your own assumptions, I don't like the result of my observations at all.

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5 August 24, 2017