Thunderbolt backward compatible with Mini DisplayPort

Discussion in 'iMac' started by Codpeace, May 24, 2011.

  1. Codpeace macrumors member

    Codpeace

    Joined:
    May 13, 2011
    #1
    Hi all,

    There are a lot of questions flying around about what is/isn't possible w/r/t the new iMac being used as a display for other devices, being used with multiple displays, etc.

    Everymac says that Thunderbolt is backwards compatible with MiniDisplayPort. See:
    "This model is equipped with Thunderbolt ports rather than a Mini DisplayPort. Thunderbolt is backwards-compatible with Mini DisplayPort-equipped displays as well as adapters that are compatible with Mini DisplayPort (DVI, VGA, dual-link DVI and HDMI). ..."
    http://www.everymac.com/systems/app...minum-27-inch-mid-2011-thunderbolt-ports.html

    So if you could do something on a 2010 iMac, why would you not be able to do it with the new 2011 iMac? Is the compatibility statement false?

    I honestly don't know, because I have never owned a Mac. Looking to buy one soon, though, so I am trying to learn as much as possible to smooth my transition from PC.

    Thanks.
     
  2. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #2
    Any mDP to something adapter will work but from what I have heard, something to mDP adapters don't (note the order). That means, you can connect monitors to the iMac using mDP adapters but you cannot use the iMac as a screen with mDP adapters. That is what I have heard, although I'm not 100% if that is correct.
     
  3. seb-opp macrumors 6502

    Joined:
    Nov 16, 2008
    Location:
    London/Norwich
    #3
    I don't think that's true, since the 27" iMac apparently supports target display mode, which would require a [something] to mDP adaptor. But of cause, not all Macs support target display mode.

    As far as I understand it, Thunderbolt is compatible with everything that mDP works with, as the mDP standard is part of Thunderbolt. The thunderbolt part comes in for specific thunderbolt accessories, for example hard drives, daisy chained displays, but obviously those accessories aren't available yet.
     
  4. peskaa macrumors 68020

    peskaa

    Joined:
    Mar 13, 2008
    Location:
    London, UK
    #4
    The 2011 iMacs support target display mode, but only when the machine being connected is also running Thunderbolt (so as it stands right now, another 2011 iMac or a 2011 MBP).
     
  5. Richdmoore macrumors 68000

    Richdmoore

    Joined:
    Jul 24, 2007
    Location:
    Troutdale, OR
    #5
    I read on here that the thunderbolt equipped imacs, target display mode only works when both computers have thunderbolt. I will look for an official apple reference.

    Found the reference: http://support.apple.com/kb/TS3775
     
  6. Codpeace thread starter macrumors member

    Codpeace

    Joined:
    May 13, 2011
    #6
    If this is true, then the statement that TB is backwards-compatible with mDP is false, no?
     
  7. peskaa macrumors 68020

    peskaa

    Joined:
    Mar 13, 2008
    Location:
    London, UK
    #7
    Semantics. The Thunderbolt port is backwards compatible with MDP if you're going one way (ie: connecting MDP display to TB) but not the other. So strictly speaking it is backwards compatible, just not 100%.
     
  8. vikingdave macrumors member

    Joined:
    Aug 27, 2008
    #8
    An odd choice of connectors

    It's really odd to me that Apple went with a connector that they have been using for display ports with Thunderbolt. If nothing else, it just creates far too much confusion, and to many questions about stuff like this. I love Apple, but this was truly a perplexing decision.
     
  9. Sylonien macrumors regular

    Sylonien

    Joined:
    May 21, 2011
    #9
    I assume that a simple hdmi / VGA / dvi cable TO Thunderbolt cable probably won't do then, if they existed? Do you think you will need some kind of convert box to be a be able to connect other devices to the Thunderbolt port on the iMac?
     
  10. dr Dunkel macrumors regular

    Joined:
    Nov 3, 2008
    #10
    With a real Target Dispaly Mode and support for industry standard ports, there would have been a 27" standing on my desk by now.

    Oh, who am I kidding, it will be there anyway, it would only have been an easier decision.
     
  11. omvs macrumors 6502

    Joined:
    May 15, 2011
    #11
    Yeah, target display mode appears to need thunderbolt on both sides. I can confirm it wouldn't work hooking my non-thunderbolt macbook pro up to my thunderbolt iMac 27". Its possible I was screwing something up, but I followed the directions pretty close. And I suspect an adapter to make this work would be pricey, since it probably needs to talk the full thunderbolt protocol now.

    But iMac driving out seems fine - both my apple dual-link adapter and my monoprice single-link adapter the same as on my laptop. So seems fully compatible in that direction.
     
  12. Repo macrumors 6502a

    Repo

    Joined:
    Feb 11, 2009
    #12
    The reason the 2011 27" iMac won't accept video inputs the way most consumers would appreciate is a combination of protocol differences and that Apple purposefully retards their products.
     
  13. seand macrumors member

    Joined:
    Mar 27, 2006
    Location:
    San Francisco, CA
    #13
    My guess is that target display mode is either an optional part of the spec or an Apple specific addition to the spec. So the Thunderbolt ports on the new iMacs could be fully compatible with the mDP spec, but not support additional functionality from previous Apple implementations of mDP.

    Here's hoping for adapters (or possibly a software update?) to allow mDP->Thunderbolt target display mode, though.
     
  14. Sylonien macrumors regular

    Sylonien

    Joined:
    May 21, 2011
    #14

Share This Page