FPS destroyed by Caverns in Young Fort

[Krast]

I am playing in a 3-year-old fort with about 80 dwarves. I have never breached the caverns.

Last night I was curious to watch my fort burn to the ground without saving. I dug a single stairwell all the way to the bottom of the map and waited for forgotten beasts to eat me. After finding 3 cavern layers my FPS dropped from 45 down to 5. I find that to be slow enough that it's not really fun. And this is the simplest possible pathing, just a single staircase.

What is happening? I think this is a pretty extreme slowdown for a fort that is 3 years old.

Is there a solution? Maybe I can delete/fill in the top two caverns with DF hack so I at least try to do the end-game stuff?

[['w']]

I read you have to limit the number of dwellers before you create the map or kill them

[Morkonan]

Originally posted by Krast:

..
Is there a solution? Maybe I can delete/fill in the top two caverns with DF hack so I at least try to do the end-game stuff?

As above - Limit the number of Cavern Dwellers in your Option's menu. (The limit is currently default-set too high according to Putnam. Should be changed, "soon.")

[Teemo]

The caverns are a huge FPS sink due to AI issues with dwarf and other unit pathing. You need to be very very careful with how much of the cavern you have available to your fort.

https://youtu.be/kG9C9f4mlMY

[Climhazzard]

Man, I was walling off a section of my caverns today when my FPS dropped from 60 to 5. It's a 5x5 embark, so I don't expect the greatest FPS, but that was a little weird. I'm not even 3 years in, just 10 months or so with 21 dwarves. I suffered until I finished the wall, then forbid the door. When I forbid the door the FPS instantly jumped back up to 60...

So I'm like.. huh. Went back out and knocked out a piece of the wall. Instantly restores FPS again.. .and a duck (pet) comes through. Rebuild the wall, still 60 fps. Damn duck.

[Doc Clarke]

Way too many cavern dwellers, especially on large embarks. We are talking several hundred. All want a piece of your CPU every game cycle. In advanced options you can lower it, but I've tried that and I still ran into a lot when I finally opened them up.

[amade]

Whenever I see my FPS drop I just pop down to the caverns to see what's stuck trying to path through. If it's something harmless/low threat I just unlock my door and the FPS jumps back. If it's dangerous I call my squad down first, then unlock the door.

Some creatures get stuck trying to path through locked doors even when there's a (much) longer route into my fortress.

[Floyd Stash]

is there a way to adjust it in an already made game?
i have a game now that i really enjoy but my fps is sitting on stable 8 right now. it's really unplayable, but i really don't want to end my game because of it :(
Also if there is a way, can anyone tell me what to edit to make it work again im not so smart.

im playing on a very default embark no changes and i think it was 4x4? or 5x5.. idk what default was.