Naive iMac 5K display question

Discussion in 'iMac' started by jamesjingyi, Mar 25, 2015.

  1. jamesjingyi macrumors 6502a

    jamesjingyi

    Joined:
    Dec 20, 2011
    Location:
    UK
    #1
    Hi guys!

    So here's my question for today. Why can't you use the retina iMac 5K as a display using two thunderbolt connections instead of one? You could just map the screen as 2x 2560x1440 displays and then sorta stitch them together couldn't you? I mean you can run dual 4K monitors with Thunderbolt so surely this is possible?

    If I am being very stupid, please tell me.
     
  2. boast macrumors 65816

    boast

    Joined:
    Nov 12, 2007
    Location:
    Phoenix
    #2
    Yes, it would be technically possible. But Apple made it physically impossible.

    Hopefully in the future someone finds a way to hack the firmware to do that, or Apple allows it, but i wouldn't hold my breath.
     
  3. jamesjingyi thread starter macrumors 6502a

    jamesjingyi

    Joined:
    Dec 20, 2011
    Location:
    UK
    #3
    So I'm not being crazy, it is possible it just isn't very elegant because it requires two cables instead of one. I seem to remember that they had to do this with the 30" Cinema display.

    Is there a standard that allows 5K displays to work?
     
  4. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #4
    You realize that 5K is still twice as many pixels as 2x 1440p displays, right?

    ----------

    You don't know that there isn't a technical limitation behind it, do you.
     
  5. andy9l macrumors 68000

    Joined:
    Aug 31, 2009
    Location:
    England, UK
    #5
    Naive iMac 5K display question

    As I understand it, the limitation is on the 5K iMac firmware/software itself, not Thunderbolt 2/DP 1.2.

    Bottom line; the 2014 5K iMac does not support TDM, at all. It never will, unless someone makes a hack.
     
  6. jamesjingyi thread starter macrumors 6502a

    jamesjingyi

    Joined:
    Dec 20, 2011
    Location:
    UK
    #6
    OOH MY MATHS IS TERRIBLE! Its 4x isn't it?

    The retina iMac is 5120x2880, means the height and width doubles from 2560x1440, meaning there are 4x the amount of pixels...

    Having said that, 5K has 14.7 million pixels and 4K has 8.8 million. 2x 8.8 million is still a lot more than 14.7 so theoretically it should work? Just output two 2880x2560 displays..

    (btw thanks for the correction, I get stupid sometimes :D)

    ----------

    Maybe when they release the 5K cinema display, they will have a better solution. I think its gonna be disappointing that the first lot with the gen 1 nMP and riM will miss out on interconnectivity though...
     
  7. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #7
    Yes, especially since you can run the same exact panel as a Dell U2715K on any 2006-2012 cMP with a lowly GTX960 at full 5K. (via 2 @ DP cables)
     
  8. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #8
    There is still NO..

    ...standard port taht has the bandwidth to run a 5 K screen from one port. The nMP can run one from 2 thunderbolt 2 ports using the 2 graphics cards. The Imac has a botched apple solution inside that is not connected through to the thunderbolt ports on it. This is why it cannot be used in target display mode.
     
  9. aevan macrumors 68000

    aevan

    Joined:
    Feb 5, 2015
    Location:
    Serbia
    #9
    Apple doesn't want to use comprimise-based solutions like that Dell 5K monitor (which is, in fact, two monitors combined into one) because of certain issues that may arise. That's why they invested into a custom TCON. External 5K Apple Displays will come with Displayport 1.3 (which comes in 2016) and not sooner. Nothing to do with botched solutions. It's the proper way to do 5K.

    ----------

    Dell U2715K is not the same exact panel, it is 2 panels combined into one with occasional graphical tearing as a result. It is not the same as the 5K screen in iMac. Doing 2-monitors-that-are-one is just not Apple's thing. They are waiting for Intel to do it the right way.
     
  10. NT1440 macrumors G4

    NT1440

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    Hartford, CT
    #10
    Creating a whole new TCON so they don't have to half ass the engineering is "botched". :rolleyes:
     
  11. aevan macrumors 68000

    aevan

    Joined:
    Feb 5, 2015
    Location:
    Serbia
    #11
    Exactly! I wish more hardware manufacturers created botched solutions like Apple, we'd have better computers today.
     
  12. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #12
    Well yeah

    Maybe a poor choice of words, I should have said they came up with a non standard solution...
     
  13. NT1440 macrumors G4

    NT1440

    Joined:
    May 18, 2008
    Location:
    Hartford, CT
    #13
    A non standard solution is exactly what they did.
     

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