Install the nvidia package with the linux kernel with the use of pacman and Calamares

TIP : use nvidia-xconfig after the reboot

We let Calamares do the hard work and after the installation we reboot and we type

sudo nvidia-xconfig

in the terminal and we reboot again.

Done.

Wondering what driver to take, read the Arch Wiki.

https://wiki.archlinux.org/index.php/NVIDIA