sudo apt-get install bbswitch-dkms

sudo vi /etc/modprobe.d/blacklist.conf

###### add this below

# Blacklist the alternative nvidia module
blacklist nouveau
# Blacklist the original nvidia module
blacklist nvidia

sudo vi /etc/modules

###### add this below

# Switch off discrete GPU
bbswitch load_state=0

###### Update initial ramdisk

sudo update-initramfs -u