xrender to slow

[Aaron]

aaron at gentoo:: xfwm4                                                        [~]
XRender test failed (target 0.0100 sec., measured 0.0528 sec.).

** (xfwm4:18899): WARNING **: The XRender implementation currently in
use on this system is too slow for the compositor

** (xfwm4:18899): WARNING **: Another Window Manager is already running


Is xfwm4  doing this on purpose? is .005 seconds that much? and can i
override this with --compositor=on?

--
Aaron Fineman