http://askubuntu.com/questions/36930/is-a-nvidia-geforce-with-optimus-technology-supported-by-ubuntu
http://askubuntu.com/questions/457446/ubuntu-14-04-nvidia-prime-is-it-supported-no?rq=1
https://wiki.ubuntu.com/Bumblebee
sudo apt-get install bumblebee bumblebee-nvidia primus nvidia-331
Usage
To run your application with the discrete NVIDIA card run in the terminal:
$ optirun [options] <application> [application-parameters]
Example:
$ optirun firefox
For a list of options for optirun run:
$ optirun --help
Normally you do not use optirun for your window manager, installations or other non graphic heavy demanding programs. The optirun command is mainly used for graphic demanding programs or for games.