The Retina iMac versus the Mac Pro, on paper – Marco.org
Marco Arment:
If I had to guess, you’ll have a long wait, and they won’t work with any Mac sold to date.
Panel yields may be tight for a while, and external displays are a low priority for Apple. The original 27” iMac’s groundbreaking LCD panel wasn’t available in an external display from Apple for almost a year after its release. But that’s not the biggest problem.
Pushing this many pixels requires more bandwidth than DisplayPort 1.2 offers, which is what Thunderbolt 2 ports use for outputting video signals. (I wrote about this a few times.) Doing it right will require waiting until DisplayPort 1.3 in Thunderbolt 3 on Broadwell’s successor, Skylake, which isn’t supposed to come out for at least another year — and Intel is even worse at estimating ship dates than I am, so it’s likely to be longer.