4 Replies Latest reply on Oct 28, 2016 12:41 PM by Intel Corporation

    NUC6i7KYK 4K over HDMI 2.0 overly blue color on Ubuntu 16.04

    sug

      Getting overly saturated blue (or missing the other color channels) running Ubuntu 16.04  on the Intel NUC6i7KYK "Skull Canyon".

       

      This also happens at 2560x1440, dropping the resolution to 1080p seems to work OK.

       

      I upgraded the BIOS from 037 -> 042 and the issue persists. Tried increased the IGP memory allocations to the maximum size and no effect.

       

      Here a picture I took with my phone and a screenshot.

       

      Monitor is an Asus PA328

       

      Picture from camera:

       

      IMG_9649.png

       

      Screenshot (looks normal when viewed on any other computer).

       

      Screenshot from 2016-10-27 18-13-11.png

        • 1. Re: NUC6i7KYK 4K over HDMI 2.0 overly blue color on Ubuntu 16.04
          sug

          Installed the Intel Graphics for Linux (Intel Graphics Update Tool for Linux* OS v2.0.2 | 01.org)

           

          Rebooted but it didnt seem to help. Running xrandr -q revealed some interesting info, system seems to think its connected by DisplayPort (DP1) instead of HDMI and my 4K seems to be limited to 30 Hz.

           

          $ xrandr -d :0 -q
          Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
          DP1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 708mm x 399mm
            3840x2160    30.00 +  30.00    25.00    24.00    29.97    23.98    24.00
            2560x1440    59.95
            1920x1200    59.95
            1920x1080    60.00*  50.00    59.94
            1920x1080i    60.00    50.00    59.94
            1600x1200    60.00
            1680x1050    59.88
            1280x1024    75.02    60.02
            1440x900      59.90
            1280x960      60.00
            1152x864      75.00
            1280x720      60.00    50.00    59.94
            1440x576      50.00
            1024x768      75.08    70.07    60.00
            1440x480      60.00    59.94
            800x600      72.19    75.00    60.32    56.25
            720x576      50.00
            720x480      60.00    59.94
            640x480      75.00    72.81    60.00    59.94
            720x400      70.08
          DP2 disconnected (normal left inverted right x axis y axis)
          DP3 disconnected (normal left inverted right x axis y axis)
          HDMI1 disconnected (normal left inverted right x axis y axis)
          HDMI2 disconnected (normal left inverted right x axis y axis)
          HDMI3 disconnected (normal left inverted right x axis y axis)
          VIRTUAL1 disconnected (normal left inverted right x axis y axis)
          

           

          Anyone who got 4K working on NUC6i7KYK, was it plug and play? Are you using HDMI 2.0 or DisplayPort?

           

          edit: Seems like HDMI 2.0 hasn't been working since 28 Aug 2016 - intel graphics - No HDMI 2.0 output from NUC6i7KYK on 16.04 -- fixes? - Ask Ubuntu

          I'll try to roll back to 4.2 kernel with 16.04 to see if I have any luck..

          • 2. Re: NUC6i7KYK 4K over HDMI 2.0 overly blue color on Ubuntu 16.04
            sug

            Look like the Asus PA328Q can only do YCbCr 4:2:0 color format on HDMI 2.0 @ 60Hz -- this doesnt mesh well hence the blue color.

             

            I tried the other ports and it wont even let me get 4K@30Hz,

             

            Luckily, its works using the mini DisplayPort at 4K@60hz.

             

            Sadly Linux VPU decoding needs much work, fans spinning decoding 4K using:

            - Totem ~150% CPU

            - VLC gives frequent black screens making it unusable.

            - mplayer seems OK but maxes out 1-2 cores

             

            They all seem to be dropping frames due software decoding but thats another issue.

             

            Gonna try Windows 10.

            • 3. Re: NUC6i7KYK 4K over HDMI 2.0 overly blue color on Ubuntu 16.04
              sug

              So I installed Win 10 Pro and was able to get 4K@60Hz over HDMI 2.0 using the same monitor and cable and everything so it seems likes its Ubuntu 16.04 drivers or kernel or something else in that stack..

               

              edit: VLC runs buttery smooth - no skipped frames @ 23% processor usage full screen. Fans still spin up but this experience is WAAAAY better than on Ubuntu. Its night and day.

               

              edit^2: More research, looks like YCbCr 4:2:0 is possible in Ubuntu but not implemented YCbCr 4:2:0 over HDMI | 01.org

              • 4. Re: NUC6i7KYK 4K over HDMI 2.0 overly blue color on Ubuntu 16.04
                Intel Corporation
                This message was posted on behalf of Intel Corporation

                Hello sug,

                In regard to your graphic issue with Ubuntu, Intel does not test and validate Intel® NUC on Linux; however, we know that a lot of NUC owners are using it successfully on many different Linux distros.

                Intel suggests you check your Linux distro's website and forums at [https://www.ubuntu.com/about/contact-us] for peer assistance with this issue.

                Also, I would like to confirm if when you run Windows on your NUC, did you have the same issues? If there was the same or another different issue with Windows, please let me know all the details.

                Please let me know how it goes.

                Regards,
                Angie