On my Intel NUC5i7RYH with latest BIOS, fresh Win 10, newest Intel graphics driver (.4424, Iris Pro 6100) I have not managed to display 4k at 60Hz on my Samsung Hu7500 UHD TV. Creating the custom resolution and then switching to 60Hz results in loss of signal.
Frustratingly, the firmware updater for the CAC-1170 also does not seem to be working: running it simply allows me to select Intel from the first dialog box and then the program does nothing, only giving me the option to exit. Running it as admin, in compatibility mode etc has had no effect. Even running the updater on my DP equipped Thinkpad results in the same behavior – the program runs but doesn’t do anything when I select Intel graphics from the opening dialog box.