Video tearing nvidia GT 540M dual screen

**readmylips** · July 31st, 2014

Hello,

I'll get right to the point:

I have a laptop (Aspire 5750G) that I run dual screen on (the built in display and a Samsung SyncMaster 2043BW). Im running ubuntu 14.04 (installed yesterday) on a nvidia GT 540M with thenvidia-331 driver with nvidia-prime installed. I have also tried other proprietary nvidia drivers from the repository with same results.

I've been busting my head in the CCSM and nvidia-settings trying to solve a dubious tearing issue:

If I have the nvidia driver disabled everything works smoothly, however when I activate it I notice tearing happening at the edges of windows as I drag them around, and also lag. I keep thinking it`s a Vertical Sync issue and I broke X over 30 times trying to fix it, so I decided to finally ask for help.

What is to be noted is that I also had the unknown display issue (mentioned here), and that my nvidia-settings GUI does not detect any displays.

I have Sync to VBlanc active in both CCSM and nvidia-settings, but disabling it has no impact. I haveDetect Refresh Rate set in CCSM and it`s now at 50, but it doesn't make any difference if I set it manually, and I can't seem to find a place to set this in the nvidia-settings.

Let's give you some data to work with:

xrandr

Code:

Screen 0: minimum 8 x 8, current 3046 x 1050, maximum 16384 x 16384
LVDS-0 disconnected primary (normal left inverted right x axis y axis)
HDMI-0 disconnected (normal left inverted right x axis y axis)
LVDS1 connected 1366x768+1680+218 344mm x 194mm
   1366x768       60.0*+
   1360x768       59.8     60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 connected 1680x1050+0+0 459mm x 296mm
   1680x1050      59.9*+
   1280x1024      75.0     60.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        75.0     72.8     66.7     60.0  
   720x400        70.1  
HDMI1 disconnected
DP1 disconnected
VIRTUAL1 disconnected

xorg.conf - Generated by nvidia-xconfig

Code:

Section "ServerLayout"
    Identifier "layout"
    Screen 0 "nvidia"
    Inactive "intel"
EndSection

Section "Device"
    Identifier "intel"
    Driver "intel"
    BusID "PCI:0@0:2:0"
    Option "AccelMethod" "SNA"
EndSection

Section "Screen"
    Identifier "intel"
    Device "intel"
EndSection

Section "Device"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:1@0:0:0"
    Option "ConstrainCursor" "off"
EndSection

Section "Screen"
    Identifier "nvidia"
    Device "nvidia"
    Option "AllowEmptyInitialConfiguration" "on"
    Option "IgnoreDisplayDevices" "CRT"
EndSection

gpu-manager.conf - I have disabled it because it kept overwriting xorg.conf

Code:

#start on (starting lightdm
#          or starting kdm
#          or starting xdm
#          or starting lxdm)
task
exec gpu-manager --log /var/log/gpu-manager.log

List of things I would like to achieve:
1. set monitors so that nvidia-settings detects them (in the hope that it would then give me more options to fiddle with)
2. set vsync using the nvidia driver to see if that eliminates the tearing
3. if none of the above work: figure out what exactly is causing the tearing

Kind regards,
Alex.

**readmylips** · July 31st, 2014

I have installed bumblebee following the accepted post here: http://askubuntu.com/questions/45255...lebee-in-14-04 and it seems to work. No more tearing.

**dunn2** · July 31st, 2014

What is tearing?? Is this an offest screen or something?

**readmylips** · July 31st, 2014

This is video tearing:

This picture is from here: http://www.tweakguides.com/Graphics_1.html . That website explains a lot of things regarding graphic hardware and software really clearly, I strongly suggest checking it out.
You can find a great explanation on tearing in the VSync chapter.