I'm looking to see if anyone has been successful in running the ASUS PB279Q at 4k 60Hz via mini DisplayPort on a MacBook Pro 2015 15".
Running via HDMI works at 4k with 30Hz only, likewise setting DisplayPort to 1.1 does the same. As soon as you set the monitor to DisplayPort 1.2 I get a no signal on the monitor with the MacBook Pro screen flashing like it can't make up its mind.
I'm running up to date OSX Yosemite have tried a genuine apple thunderbolt to thunderbolt cable (mini dp > mini dp) as well as a cheaper mini dp to dp. According to https://support.apple.com/en-au/HT202856 4k should work as expected using SST.
Any further ideas?