Are you still on "spinning rust", mechanical hard drives? If so, installation on a SSD should do wonders for you. That said, the game is still fairly unoptimized, and as @Polonius Ulf wrote, they definitely need to do something about the world save.

I get stutters as well, even though my fps show between 40-60 fps.

That's the autosave, the bigger you build, the longer it will take.

The time-based autosaving is an ugly kludge which the devs really need to replace with event-driven saves. (When you sleep, when you go through a portal, when you sit down, on demand).

The save method should invoke the garbage collector, too. It seems that it doesn't, because I get double-whammied a lot.

Maybe they will take the time for this after Mistlands.

Originally posted by Lil Puppy:

That's the autosave, the bigger you build, the longer it will take.

Fresh world. It generally warns before a save, right? It's stuttering without doing that.