See my Mac wish list.
The Dell UltraSharp 32 Ultra HD 8K Display will hit the market in early spring, raising the question of whether any Macs can drive that glorious 33.2 megapixels.
Update May 2017: the Dell UltraSharp 32 Ultra HD 8K Display is now shipping.
The GPU power along with the bandwidth required to drive four 4K displays is just emerging, but the 2016 MacBook Pro looks like it might be capable enough.
Apple specifications for the 2016 MacBook Pro state:
Up to two displays with 5120-by-2880 resolution at 60Hz at over a billion colors
Up to four displays with 4096-by-2304 resolution at 60Hz at over a billion colors
A 4K display is 3840 X 2160; thus four displays at 4096 X 2304 offer 13.7% more bandwith than required to drive an 8K display. Of course, an 8K display would have to be the only display, unless a 2017 Mac Pro arrives that can drive six or eight 4K displays. But with a MacBook Pro, presumably the internal display remains usable, so a dual display system looks possible.
Using two Thunderbolt 3 cables, it should be possible to drive an 8K display on the 2016 MacBook Pro in 10 bit color*, at least in terms of the required bandwidth, using a trick similar to how a 5K display was possible in previous Macs: drive each half of the display with one of the Thunderbolt cables, that is, Multi Stream Transport. The same trick might work for 8K. Perhaps Apple or Dell will weigh in on this possibility soon.
* The Apple specifications indicate “billions” which means 10-bit color.
Potential for an iMac 8K
Since a 32-inch 8K panel now exists, and the 2016 MacBook Pro already has the bandwidth to drive an 8K display, an iMac 8K is technically possible with today’s technology.
An iMac 8K could use a custom graphics solution to push those 32 megapixels, just as the iMac 5K does. There is no need for wait for standards to evolve to support external 8K support; it can be done internally with a proprietary solution. The main issue is cooling, but Apple should be able to engineer an appropriate GPU cooling system. And since the 2016 MacBook Pro is an even greater cooling challenge, and it can drive four 4K displays, it hardly seems like an iMac 8K should have any barriers to supporting an 8K built-in display.
The Dell UltraSharp 32 Ultra HD 8K Display will apparently sell for $4999. Even assuming that Apple could use its considerable volume to get that price down to $2000 or so, it would make an iMac 8K with the necessary GPU power something hitting the $6K to $8K range in price. So even though it appears to be ideal for an 32" iMac 8K, cost is likely to push off such an iMac. Then again, Apple has surprised us in the past, and could do so again, particularly with its failure to innovate for several years now.