According to the support page https://www.intel.com/content/www/us/en/support/articles/000005571/mini-pcs.html "Setting Up Multiple Displays for the Intel® NUC", the NUC6i7KYK should be able to support three 4K screens.
I'm using Ubuntu 18.04 running Linux kernel 4.15.0-20
I'm using three LG 27UD68P-B screens (With "Super Resolution+" and "HDMI UHD Deep Color" enabled):
As soon as I attach the HDMI cable things start going wrong, but each environment goes wrong a bit differently:
So how can I solve this?
Thank you for joining the Intel Community Support.
Intel does not test and validate Intel® NUC on Linux. However, we know that a lot of Intel® NUC owners are using it successfully on many different Linux distros. I recommend you to check your Linux distro's website and forums for peer assistance with this inquiry.
Additionally, you may visit the following website: https://01.org/linuxgraphics
You are right. The Intel® NUC Kit NUC6i7KYK supports three 4K displays, but you have to connect one display per video port.
As you already mentioned, the following configuration is recommended under Triple Display Configurations:
I hope this helps.