Not sure why the makers of Ubuntu always opt for stupid defaults. I had to do some digging to figure out why the graphics drivers on my little media computer were causing tearing and horizontal refresh flickering when I was watching video.
Come on guys, vertical sync (vsync) should be ON by default on Intel graphics drivers. No one is using these things for games, and it’d improve the gaming experience anyways. This is a no brainer.
Put this in
Section "Device" Identifier "Intel Graphics" Driver "intel" Option "TearFree" "true" EndSection