2011 Mac Mini Thunderbolt to Display Port Snow

Discussion in 'Mac mini' started by shortcut3d, Dec 18, 2011.

  1. shortcut3d macrumors 65816

    Joined:
    Aug 24, 2011
    #1
    I'm currently getting snow on my 2010 27" iMac in target display mode connected to my 2011 Mac Mini Server daisy chained to a LaCie Thunderbolt Little Big Disk. It occurs in both Windows 7 and OSX Lion. The issue is sporadic and at times the display is stable. No issues with the iMac display in normal mode or without the daisy chain.

    Any ideas would be appreciated.
     
  2. paulrbeers macrumors 68040

    Joined:
    Dec 17, 2009
    #2
    Anandtech posted awhile back that the only way to get an old 27" non-Thunderbolt ACD to work with 2011 Thunderbolt enabled devices is to put another Thunderbolt Device (i.e. hard drive) between the Thunderbolt equiped Mac and the ACD because the signal after the Thunderbolt Device (i.e hard drive) is only displayport video. So my guess is, the snow is caused because after your Little Big Disk, the signal coming from it is only standard Displayport Video and NOT a Thunderbolt video signal, thus the Thunderbolt equipped iMac is unable to display the image properly.
     
  3. shortcut3d thread starter macrumors 65816

    Joined:
    Aug 24, 2011
    #3
    Yes, I am aware of the Anandtech article. However, I am using a 2010 27" iMac not the 2011 model.
     
  4. Twonails macrumors newbie

    Joined:
    Dec 20, 2011
    #4
    Flickering screen MBA TBolt to 24' Apple Dport LCD

    I have a every similar problem here.
    When using-
    1) MBA TBolt to 27' 2010 iMac via display port input -> no problems

    2) MBA TBolt to Little Big Disk to 27' 2010 iMac via display port input -> screen flickers with frequent instability

    3) MBA TBolt to 24' 2008 Apple LCD via display port input -> no problems

    4) MBA TBolt to Little Big Disk to 24' 2008 Apple LCD via display port input -> screen flickers with frequent instability

    All evidence points to the Little Big Disk. The output from the LBDisk to both the 27' 2010 iMac and the 24' Apple LCD show instability.
    I have contacted Lacie and their tech wrote back asking me to check my cables, suggesting they were not in the best condition. The cables are fine. It is the output from the LBD to display port input that is the problem.

    Any one else experiencing this issue?
     
  5. philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #5
    here is an opinion this will be a problem for any t-bolt device. because the video passing through 2 t-bolt chips and the lacie chip is ending up in a non t-bolt device. If one of you are in NJ I have a promise pegasus I could run the device over to your house in person.


    and do a mini to( t-bolt cable) to ( promise pegasus ) to 2010 iMac/display


    if it is flawless then the problem is in the lacie device. if it flickers then apple is needs a t-bolt patch to allow for daisy chain of 2010 iMac/display
     
  6. shortcut3d thread starter macrumors 65816

    Joined:
    Aug 24, 2011
    #6
    Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A406 Safari/7534.48.3)

    Right now the 2010 27" iMac in target display mode is stable following a firmware fix / patch applied to the dual 240GB OCZ Vertex 3 SSDs. I think the issue is noise in the LaCie.

    I had temporary stability by switching the order of the cables (top to bottom) on the LaCie. However, the instability would return.
     
  7. shortcut3d thread starter macrumors 65816

    Joined:
    Aug 24, 2011
    #7
    Confirmed. SSD firmware patch did not fix the issue.
     
  8. elliotn macrumors regular

    Joined:
    Sep 5, 2011
    #8
    I'm not sure I've understood the test you're proposing, but I have an Eizo CG275w monitor connected to a Promise Pegasus connected to a mini Server and the monitor is working fine (no 'snow').
     
  9. philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #9
    your setup could mean the lacie is the "bad Guy"

    or it could mean the older apple display is the bad Guy. i.e. if we put a lacie in your setup (No promos p)
    and got snow then I would think the lacie is the problem. if we put a apple display in your setup and kept the promos p then I would think the apple display is the villain
     

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