NVS 810 4x2 video tearing.

Hi, I’ve developed an video-wall aplication with linux + xorg, but the video playback is tearing.

The system:
NVS 810, driver 418.56
OS: Debian 9 (debootstrap) + xorg
Player: Programed with python3 + selenium to control a firefox instance.
I was forced to use xinerama option due the xorg panning function (the only way I found to disable it).

The NVIDIA documentation for linux is very poor, some options like “Connected Monitor” args I had to figure out by testing.
And the BaseMosaic + SLI was very confusing in the docs.

Unfortunately, I had to deploy the system to the client with this problem, but I have the option to go there and update the software part.

xorg.conf code

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "1"
    Option "StandbyTime" "0"
    Option "SuspendTime" "0"
    Option "OffTime"     "0"
    Option "BlankTime"   "0"

Section "Files"

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Samsung SyncMaster"
    HorizSync       30.0 - 81.0
    VertRefresh     60.0 - 75.0
    Option         "DPMS" "false"

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "NVS 810"
#    BusID          "PCI:3:0:0"

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "nvidiaXineramaInfoOrder" "DFP-1"
    Option         "metamodes" "GPU-0.DP-1: 1920x1080 +0+0 {rotation=invert}, GPU-0.DP-0: 1920x1080 +1959+0 {rotation=invert}, GPU-0.DP-3: 1920x1080 +3918+0 {rotation=invert}, GPU-0.DP-2: 1920x1080 +5877+0 {rotation=invert}, GPU-1.DP-1: 1920x1080 +0+1190, GPU-1.DP-0: 1920x1080 +1959+1190, GPU-1.DP-3: 1920x1080 +3918+1190, GPU-1.DP-2: 1920x1080 +5877+1190"
    Option         "MultiGPU" "Off"
    Option         "SLI" "off"
    Option         "BaseMosaic" "on"
	Option         "ConnectedMonitor" "GPU-0.DFP-0, GPU-0.DFP-1, GPU-0.DFP-2, GPU-0.DFP-3,GPU-1.DFP-0, GPU-1.DFP-1, GPU-1.DFP-2, GPU-1.DFP-3"
    SubSection     "Display"
        Depth       24


Use ForceCompositionPipeline=On in your MetaModes settings to mitigate tearing with non-compositing window managers.

Ok. I will try next week!