I run two 4k@60hz Screens on my 1080 Card, a Philips 40 inch Screen and a Samsung 40 inch TV. The Samsung TV is actually over 20m cable. In order to get an image on my HDMI TV, i had to reduce the ColorSpace from FullRGB to Yuv420.
The Nvidia-Settings although have a property, where the ColorSpace can be set, but it only offers FullRGB or Yuv422.
I then found out, that there is an option in nvidia-xconfig:
This actually alters the xorg.conf file and adds ForceYUV420=TRUE and forces the ColorSpace to the desired value.
Unfortunately, there seems to be no official documentation on ForceYUV420 available, and I don’t know if this is an experimental feature, that could be removed one day?
Does anybody has more information about this option?