Use Old iMac for New Mini's Second Display?

Discussion in 'iMac' started by CoMoMacUser, Feb 10, 2014.

  1. CoMoMacUser macrumors 6502a

    Jun 28, 2012
    My early 2008 iMac is getting slower, so I'm probably going to replace it with a Mini when the new models come out. I'm self-employed, and the Mini would be my new work machine. I think it would be helpful to have a second display because I typically have multiple things open simultaneously, and it would be a lot more productive to have them available side by side.

    Can a Mini use an iMac as a second display? If so, any drawbacks?

    Also, if the iMac's hard drive craps out, that eliminates the ability to use it as a display, right? AFAIK, there's no way to use the iMac just as a monitor; it has to be functional as a PC to be able to display video from an external source.

  2. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    your iMac has no video-in port.

    you can buy dongles but they can cost more than a monitot
  3. xraydoc macrumors demi-god


    Oct 9, 2005
    I'm not sure if the 2008 iMacs support Apple's Target Display Mode. If you do a Google search for Target Display Mode, you'll find all you need to know.

    What I do recall:

    - only the 27" iMacs had this ability, the smaller ones did not (not sure about the current Thunderbolt-equipped 21" models).

    - I do not recall if the 2008 or 2009 iMacs support Target Display Mode.

    - the 2010 27" iMac will do Target Display Mode with a miniDisplayPort-equiped Mac (this includes Thunderbolt-capable Macs such as the current Mac minis, but does not include Macs without an mDP port)

    - the 2011, 2012 and 2013 27" iMacs will only do Target Display Mode with another Thunderbolt-equipped Mac (which a current Mac mini will have).

    - the iMac has to be booted and running OS X for Target Display Mode to work. If the iMac won't boot, the TDM won't function.

    With these caveats in mind, the TDM function works quite well. I occasionally connect my MacBook Air to my iMac and use the iMac's display if there's something I need two displays for (like rehearsing a Keynote; the iMac acts as like the display the audience sees and the MacBook Air's screen shows the presenter view).
  4. biohead macrumors 6502

    Jun 18, 2010
    West Drayton, UK
    From Apple's KB article (

    27" Late 2009,
    27" Mid 2010,
    21.5" + 27" Mid 2011,
    21.5" + 27" Late 2012

    So no, you can't use your early 2008 as a TDM monitor with a mini unfortunately.
  5. CoMoMacUser thread starter macrumors 6502a

    Jun 28, 2012
    Thanks, everyone. I guess I'll buy two monitors.

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