Thank you for joining the Intel communities.
I’m sure you will be able to run two monitors with this unit with no problem; this unit supports the following resolution in single mode:
Max Resolution (HDMI 1.4)‡
Max Resolution (DP)‡
I did some research after posting, and according to Section 184.108.40.206 the spec sheet, it actually cannot handle dual 1440p monitors at 60Hz refresh rate: http://downloadmirror.intel.com/25507/eng/NUC6i5SYB_NUC6i3SYB_TechProdSpec01.pdf
So sadly, ivanu_intel, I think it is not capable of my needs.
I think it does. Check the technical document you linked to, chapter 220.127.116.11.1. With DP1.2 multi-stream two monitors at 2560 x 1600 @ 60 Hz are supported. Most probably one monitor using HDMI and one on DP would also work, though this is not documented. I'm using HDMI with a single 1440p@60Hz monitor and this is also not documented.
I'm running 2x1440p (Two Dell 2515H displays).
I've tried to use Displayport 1.2 mode on the displays for DP daisy-chain, that did not work though. Still havn't figured out if that's because the NUC has some bug (it should support 1.2) or if the Linux drivers are not supporting it.
Right now I'm running 1 monitor via DP and one via HDMI (Do note, not all displays support 1440p on the HDMI port even though your NUC does).
The problem, I think, isn't DP 1.2 (e.g. the higher bandwidth possible) but multi-stream support. What distribution and kernel are you using? I think Linux does support multi-stream but only recently (I don't have a setup to test, though).
I'm using Xubuntu 15.10, running the latest kernel 4.5-rc1. Still seeing lots of issues related to the hardware acceleration btw. Chrome and mpv crashes with it turned on.
Sadly, the VP2770's don't support daisy-chaining, and so I'd have to use an MST hub - but as far as I know, all such hubs are buggy and bad, at least if online reviews are to be believed. It would be much simpler to just have them each on a separate port.
As fredlb wrote HDMI+DP is possible for 1440p@60. If your monitor's HDMI support the higher bandwidth (I think 1.4b is needed) you should be fine.