What I mean by parameters is.. don't have magma if you don't need it. don't have HFS if you don't plan on breaching it. Don't have three cavern layers if you only need one.
Don't have above ground plants and trees if you don't use them (belowground farming FTW!).
Don't have 16 races if you need 2 (dwarves, goblins)
Don't have a 127x127 world when 17x17 is perfectly fine for fortress mode.
Don't have unlimited civ sites when none will do.
Don't have a living mountainhome when a DEAD one will do.
Alternately, you can even mod dwarves to use above ground crops and permit civ/sites to appear in ALL biomes, and remove the caverns and magma entirely. Sure, it's a little different, but wow, the FPS gain is amazing.
All these do little impact on game FPS, only the time of save/load.
The MAIN part in killing FPS plays the QUANTITY of all that single things on your base. Stones, blocks, wood, plants, meat, threads, CLOTHES, corpseparts etc. Unrevealed caves don't count.
Proof: have 80 dorfs+15k stones/bars (without bins) +50k cloth/thread/wood/food = 40fps
Annihilated all stockpiles with raising bridge, leaving 80 naked dorfs = 190fps
The second part is the quantity of moving beings - dwarfs and animals. ONE single room with animals and "pet-closed" door can lower FPS to 10% of normal.
Proof: 80 working moving dorfs = 60 fps, 80 idle almost standing dorfs = 95fps
Third part are for flowing water and magma.
Have no proof with numbers.