In order for me to watch HD videos without tearing, I need to disable my Composite setting in xorg.conf Section Extensions    Option Composite DisableEndSectionBut I love my transparency, so, how do I enable and disable it without restarting X? (Preferably using command line)
Disable Composite without restarting X
xorg;video;xfce;composite
Found a better way to do it, just:MenuSettings Window Manager Tweaks  Compositor Tab  Uncheck Enable display compositingI think this is better since it doesn't involve installing new application and it did help me prevent tearing when watching HD movies. 