First, my hardware:
- Dell U3011 2560x1600 (it has HDMI, but you get only 1080p with HDMI, so always using DP)
- NUC Skull Canyon (it is what i use mostly, but also have a NUC5/NUC6, and NUC7)
At first I was using a 6' mini DP->DP cable and I would get the occasional black out (lasted about 1 sec, usually happened as I sat down at the desk). The Dell U3011 does not suffer from the problem of not re-acquiring the signal, it was a minor annoyance.
Switched to a 3' mini DP->DP cable and the problem went away. Both cables were the same brand, purchased on Amazon. I forget the brand (maybe was 'cable matters'?).
And right now I'm using an active HDMI->DP adapter (from 'Go Fanco'; plugs into USB and HDMI on NUC6sc, plugs to DP on monitor) to a 6" DP->DP cable (again 'cable matters'). No blackouts with that scenario. No idea if the adapter supports 4k. I have no 4k monitors here (4k would not make sense on a 30" monitor, my preferred size... would need 5120x3200 for my needs).