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I would expect target display mode to be there, but to require Thunderbolt as input (like the 2011 iMac's).

I'd be less certain that you'll be able to input retinal resolutions -- especially if the 27" has a full 5120x2880. Assuming I did my math right, that would require ~20GB/sec, and the Thunderbolt only has 10GB/sec for the video stream...? Even 21" at 3840x2160 looks like it wouldn't work -- ~12GB/sec.
 
I would expect target display mode to be there, but to require Thunderbolt as input (like the 2011 iMac's).

I'd be less certain that you'll be able to input retinal resolutions -- especially if the 27" has a full 5120x2880. Assuming I did my math right, that would require ~20GB/sec, and the Thunderbolt only has 10GB/sec for the video stream...? Even 21" at 3840x2160 looks like it wouldn't work -- ~12GB/sec.

It wouldn't because the max output of thunderbolt is 1600p.
 
Yes, just like the 2011 models do.

As has been said above, if the iMac gets a big jump in resolution (I'm not expecing a full double-dpi upgrade, that would be silly on a 27" display), you may be limited with the resolution you can display from an external source over Thunderbolt.

As I recall the 2010 models only supported 720p or 1080p in target display mode, so it wouldn't be surprising to see something similar if the 2012 model outstrips the ability of DisplayPort/Thunderbolt to drive it.
 
2012s are out - experiences

So, anyone tried yet to hook up an xbox/ps3/blu ray player to his new iMac? I ordered the 21inch-model, should be delivered in 2 weeks, and i´m wondering if i could hook up a ps3 to it.
 
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