it also depends on your PC strength/capabilities. But most of the fps tanking is just ♥♥♥♥♥♥ optimization on the devs end. The mod community has taken care of these issues in a lot of thier different HD graphic packs and stuff. My fps doubled when i installed some of them. They also have some optimization mods as well. None of them require valheim plus and are just graphical updates basically. The game is still vanilla if you prefer it that way. But honestly the mod community has been working circles around this slow ass dev team. Considering valheim isnt even a new game just a re release of the failed first atempt. It came out over a decade ago.