Warning: As of October 2020, the NVIDIA driver does not support the Linux kernel 5.9. [1] - NVIDIA - ArchWiki
No need to run as root.
This tip feels kind of obsolete - but anyway…
When you run nvidia-settings to create your X configuration - no need to use root.
Just run the application using the menu launcher.
When you have adjusted your settings select the Save to X Configuration File from the tab X Server Display Configuration and when prompted for a file name - use your home e.g.
~/nvidia-xorg.conf
Depending on your use case you will either copy the file to /etc/X11/xorg.conf.d/20-nvidia.conf or you may want to replace the mhwd generated file in /etc/X11/mhwd.d/nvidia.conf e.g.
There is only one place where you save the settings to be applied system wide
In the left pane of the Nvidia settings window
In the corresponding right pane you have
In the botton of the left pane there is nvidia-settings Configuration and the corresponding right pane is also a save settings - but this one is creating a rc file which you can load per user base using the -l, --load-config-only option
$ nvidia-settings --help
...
-l, --load-config-only
Load the configuration file, send the values specified therein to the X s
erver, and exit. This mode of operation is useful to place in your xinit
rc file, for example.
...