Originally posted by AdventChildVII:

as my town gets bigger an bigger ive noticed a slow decrease in fps so i went on to a singleplayer map and flattened an area the size of walmart and BOOM fps goes downnnn.
reddit says this about it.
https://www.reddit.com/r/valheim/comments/lqcr88/reason_behind_low_fps_and_huge_instance_numbers/

I've flattened a large area with a moat, and my fps always drops near it but rises away from it.