install cuda -- turn off Nouveau

 before install cuda,Nouveau need to be turned off

create a new text file

$ sudo nano /etc/modprobe.d/blacklist-nouveau.conf

in blacklist-nouveau.conf

 

blacklist nouveau

options nouveau modeset=0

then, rebuild kernel and reboot

$ sudo update-initramfs -u

$ sudo reboot 

after reboot make sure Nouveau have been shut down

$ lsmod | grep nouveau