Comment 7 for bug 1357804

now you can use nvidia proprietary driver 346

Just use our friend Michael Marley's ppa :

Add ppa, update cache, install nvidia-346 and reboot :
sudo bash -c "sudo add-apt-repository ppa:mamarley/nvidia -y && apt-get update && apt-get install nvidia-346 -y && reboot"

I hope nouveau will improve...