Ubuntu XPS 8700

Nvidia Geforce GT 720 installed on Ubuntu 14.04 using

 $ sudo add-apt-repository ppa:xorg-edgers/ppa
$ sudo apt-get update
$ sudo apt-get install nvidia-340

source:  http://linuxg.net/how-to-install-the-nvidia-340-24-driver-on-ubuntu-14-04-ubuntu-13-10-ubuntu-12-04-and-derivative-systems/