Is there any kind of official statement as to the support of those existing and upcoming UHD (3840x2160Hz) PC screens that operate in tiled mode (so they operate in DisplayPort MST mode and get two 1920x2160 @60Hz signals that the driver puts together to a single display (just like you get one single 2560x1600@60Hz from a dual link DVI connection). AFAIK, all 4K screens right now operate in this mode.
Only the 4th gen Core I Series H models apparently support 3840x2160@60Hz according to this:
Yet, the data sheet also states (http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/4th-gen-core-family-mobile-u-y-processor-lines-vol-1-datasheet.pdf table 9) that the U series can drive two displays at 3200x2000@60Hz. So, spec wise, there's enough pixel throughput to drive those tiled beasts, but it all comes down to the drivers.
Nvidia manages, AMD too (all with recent drivers and far from all cards) - what's intel's take on that? I read the sticky on collage mode for 4Kx2K - I just found some new drivers on WindowsUpdate that aren't yet on intel.com and using some creative option chosing, I actually managed to get collage mode working so my 4K screen now runs at full resolution at 60Hz, but since collage mode is meant for disjoint displays, it's not really the full experience (e.g. the taskbar only spans one screen or is duplicated, you can go full screen by dragging a window to the top, the usual you get with a dual screen setup).
Can we expect driver support for 4K tiled displays in MST mode on 4th gen core I processors in the future to drive 4K displays at their full resolution at 60Hz (so that not only do we get 60Hz, but Windows will see one single display and acts accordingly)?