Bumblebee allows you to run specific programs on the discrete graphic card, inside of an X session using the integrated graphic card.
It's written by Martin Juhl and published under GPL v3.
What it does - and does not
Actually only Ubuntu and Fedora(maybe Debian, Arch and Mint but not tested) is supported by this script, but Martin is working on to porting on other distros and make his script more distro-independent. For info about state of work in distro porting or to help in porting please see https://github.com/MrMEEE/bumblebee/issues/7
Currently this application doesn't shut down the nvidia card when not used, nor balance the load between the two cards (cf README).
git clone https://github.com/MrMEEE/bumblebee cd bumblebee ./install.sh
You can compare display performances with and without bumblebee :
glxgears optirun64 glxgears
Use the bumblebee-bugreport script to create a nice bug report that you'll send here.