last link in thunderbolt daisychain

Discussion in 'Mac mini' started by uncleMonty, Nov 14, 2012.

  1. uncleMonty macrumors regular

    Jun 8, 2012
    Can the last link in a thunderbolt daisy-chain be a non-thunderbolt monitor, using miniDisplay port?

    For example, Mac mini <--> external SSD <--> apple cinema display 30" (using miniDisplay port adaptor plugged into the SSD's second thunderbolt port)

    I'd be very grateful if someone could try this and let me know. If not, no Mac mini for me.
  2. paulrbeers macrumors 68040

    Dec 17, 2009
    Yes in order for any displayport monitor to work on a thunderbolt Mac, you have to have another Thunderbolt device between your computer and the monitor. That is what Anandtech found out last year and posted on their review site.
  3. uncleMonty thread starter macrumors regular

    Jun 8, 2012
    Thanks paulrbeers. I looked for a review on Anandtech that addressed this, and found this in his review of the new Apple displays:

    "If you connect a Mac to the Thunderbolt Display what is sent is a Thunderbolt signal. DisplayPort is broken off and sent to the display but there's no way to propagate an additional DisplayPort signal to any other non-TB displays in the chain. The output on the Thunderbolt Display is literally a Thunderbolt output, it can't double as DisplayPort."

    (that is here: )

    So it appears it is not possible with the new Apple displays to add a displayPort at the end. I couldn't find anywhere where Anandtech discusses the same issue with respect to Thunderbolt storage devices between the Mac and the DisplayPort monitor. Do you remember where you saw it?


    Ok, I found where someone reports they were able to do what I wanted on a 2011 Macbook Air in this thread:

    They used a Seagate GoFlex drive. The term to search for was "displayPort passthrough".
  4. paulrbeers macrumors 68040

    Dec 17, 2009
    You missed the part at the bottom of the page you linked to:

    I tested multimonitor functionality with a 27-inch LED Cinema Display as well as a second Thunderbolt Display. In the case of the Cinema Display, as expected, I couldn't get video out of the port on the Thunderbolt Display. Connecting the Thunderbolt Display to a Promise Pegasus and then connecting a Cinema Display to it worked however. I also woke up the MacBook Pro's internal display and confirmed that I could get all three functioning simultaneously. There's a definite slowdown in UI frame rate with two 27-inch panels being driven by the MacBook Pro's integrated Radeon HD 6750M. It's not unbearably slow but kiss any dreams of 30 fps goodbye.

    Basically as you found, as long as something else is between the Mac and the displayport monitor you are fine...

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