DP1.4 MST for Dell up3218k 8k/60Hz on GTX 1080?

Graphics / Linux FreeBSD/Solaris
1

Hi,

I have a Dell up3218k 8k monitor and an Nvidia GTX 1080 using the 381.xx driver train. I can drive the monitor at 8k/30Hz using one DP 1.4 cable. I can get 8k/60Hz using 2 DP 1.4 cables where the monitor stitches the two halves together but it appears to X11 as two screens. As far as I can tell the monitor is designed to use MST to provide a seamless one screen 8k 60Hz display. What can I do to make the nvidia driver run that config?

2

kev009,

Were you able to resolve this? I just got the same monitor and share the same question. The windows driver works fine @ 8K/60Hz but on Ubuntu I can get it to work either @ 8K/30Hz (i.e. it’ll only “listen” to one of the two displayport cables) or @ 8K/60Hz but then by treating the left half of the display as one screen and the right half of the display as another in X11. The latter solution is not practical as when you select “full screen” in an app, it’ll only apply the window to the left or the right side of the screen.

Let me know,

Thanks!

Hans.

3

I’m getting the same monitor shortly, but I currently use a high-end, two-cable 4K display, and this is the (relevant part of the ) xorg.conf that works for me. I hope it guides you to a solution for the Dell 8K.

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Eizo FDH3601"
    HorizSync       31.0 - 140.0
    VertRefresh     23.0 - 61.0
    Option         "DPMS"
EndSection

Section "Monitor"
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "Eizo FDH3601"
    HorizSync       31.0 - 140.0
    VertRefresh     23.0 - 61.0
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "Quadro K5000"
EndSection

Section "Device"
    Identifier     "Device1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "Quadro K5000"
    BusID          "PCI:5:0:0"
    Screen          1
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    SubSection     "Display"
        Depth       24
    EndSubSection
    Option         "TwinView" "1"
EndSection

Section "Screen"
    Identifier     "Screen1"
    Device         "Device1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "Stereo" "0"
    SubSection     "Display"
        Depth       24
    EndSubSection
    Option         "TwinView" "1"
EndSection

Section "Extensions"
    Option         "Composite" "Disable"
EndSection
4

I was manually specifying xinerama info like this, to define one xinerama screen:

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    30
    Option         "Stereo" "0"
    Option         "UseEdidDpi" "FALSE"
    Option         "DPI" "144 x 144"
    Option         "nvidiaXineramaInfo" "TRUE"
    Option         "nvidiaXineramaInfoOverride" "7680x4320+0+0"
    Option         "metamodes" "DP-2: 3840x4320 +3840+0, DP-4: 3840x4320 +0+0; DP-2: nvidia-auto-select +3840+0, DP-4: nvidia-auto-select +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       30
    EndSubSection
EndSection

This made kde5 work right without two regiocns on the display, and there was no tearing. Forcing nvidiaXineramaInfo seems to disable randr sreen data, and I think this causes issues with Firefox GPU acceleration. Supposedly FreeBSD driver version 387.32 fixes this to report one screen for tiled monitors.