I just installed bumblebee and primusrun in my Ubuntu 12.04.
I can execute applications like totem successfully through vblank_mode=0 primusrun totem in terminal. My doubt is how do I edit the .desktop files located at /usr/share/applications to choose nvidia as default?
I changed this line at totem.desktop file: Exec=vblank_mode=0 primusrun totem %U
But when the file is with this configuration I cannot launch totem through Unity launcher. Am I doing something wrong here?