xfwm4?josesito@josesito-pc:~$ xfwm4
XRender test failed (target 0,0250 sec., measured 0,0375 sec.).
** (xfwm4:5878): WARNING **: The XRender implementation currently in use on this system is too slow for the compositor

** (xfwm4:5878): WARNING **: Another Window Manager is already running
josesito@josesito-pc:~$