Normally, my rig (RTX 2060 6GB, i5-11400F, 16GB RAM, dedicated game SSD) gets 80-100 FPS everywhere else in the game -- EXCEPT the Mountain biomes, specifically during snowstorms. It's a hard 20-30 FPS then.

I tried messing with every setting over the course of several hours yesterday, matter of fact, trying to figure out what (if anything) could be done to maybe sniff out what's happening there. None of the settings really seemed to have an effect other than general speed-up. I would still be looking at roughly the same percentage of lost FPS. (It'd get up to about 110-120 max with settings dropped to "where we're going we neither need nor want eyes" but drop back down to the 30-50 FPS neighborhood during the snowstorms.)

~70% performance reduction is a very steep dropoff. I can live with it, but my friends refuse to play with me when I build Mountain bases (which are, of course, the best places to build for raids).

Now to build a hot tub and test what happens with the steam...