imac 27-inchIf you’re considering using your brand new 27-inch iMac as an external display to a MacBook Pro or a Mac Pro you’ll find this recent support document from Apple to be rather useful.

With Target Display mode, you can use your 27-inch iMac with Mac OS X as an external display. Connect any computer or other device with a Mini DisplayPort to your 27-inch iMac using a Mini DisplayPort to Mini DisplayPort cable or using a converter that converts other electrical, video, and audio protocols from another source device to Mini DisplayPort compliant signals.  (Cables and converters available separately.)

To use a 27-inch iMac in Target Display mode with another computer as the source:

  1. Make sure both computers are turned on and awake.
  2. Connect a male-to-male Mini DisplayPort cable to the Mini DisplayPort on each computer. The 27-inch iMac will enter Target Display Mode and display content from the source computer. Note: If you are connecting two 27-inch iMacs, connect a Mini DisplayPort cable to each computer and press Command + F2 on the 27-inch iMac keyboard that you will use as an external display.
  3. To leave Target Display mode, press Command + F2 on the keyboard of the 27-inch iMac that is in Target Display mode. To return to Target Display mode, press Command + F2 again.

Visit the Apple website for full information.