Section "device" 
 Option "RenderAccel" "True" 
 Option "DisableGLXRootClipping" "true" 
 Option "BackStoring" "True" 
 
Section screen 
 Option "AddARGBGLXVisuals" "True" 
 
Section "Extensions" 
 Option "Composite" "Enable" 
 Option "RENDER" "Enable"