I got a better performance in gaming with linux-amd-znver2 on my AMD Ryzen 5 5600X.
I installed it because I get this output when calling this command:
> gcc -c -Q -march=native --help=target | grep march |head -1|awk '{print $2}'
znver2
Searched for "znver2" in Pamac, there's only linux-amd-znver2 listed (AUR).
For those who are interested with this kernel flavor, see this comment on how to download a pre-built package.
The drawbacks with this kernel flavor: Some CPU information cannot be read.
(1) I used linux-tkg-bmq before. In order to display the CPU power consumption in MangoHud, I have to open GOverlay and enable "Fix for power draw on intel CPUs". Yes, the tooltip says "intel", but it works with my AMD CPU.
But when I use linux-amd-znver2, it doesn't work 
(2) I got this error when calling paleofetch:
> paleofetch
paleofetch: unable to retrieve login name
> paleofetch --recache
paleofetch: unable to retrieve login name
It's been discussed before. But as you see, I still got the same result with paleofetch --recache.
uname works well though:
> uname -r
5.11.12-AMD-znver2
