Proprietary nvidia driver isn't supported by kernel 5.9, you'll have to wait mid-november for nvidia to make it usable.
https://forums.developer.nvidia.com/t/nvidia-driver-not-yet-supported-for-linux-kernel-5-9/157263
@nikolal
I believe Linus Torvalds had something to say about things like this:
https://www.youtube.com/watch?v=_36yNWw_07g&t=13
@nikolal updating nvidia drivers is the riskiest thing I do with my Linux.
@ParmuTownley
Wait untill you learn about gpu passtrough. I've bricked my laptop twice trying to make it work.
Seems this was fixed a week ago, feel free to update on 5.9 kernel with nvidia drivers.
https://bugs.archlinux.org/task/68312