A quick recipe that worked like a charm
Download driver from http://www.nvidia.com/object/linux-display-amd64-313.30-driver.html
then run:
sudo service lightdm stop
sudo chmod a+x NVIDIA-Linux-x86_64-313.30.run
sudo ./NVIDIA-Linux-x86_64-313.30.run
You may need to run the last command twice (including a reboot) if you are already running Nouveau drivers. Follow the on-screen instructions.