I'll try embarking on a low-lying area, although my current fort was pretty low as it was. The elevation map had the forest biome listed as a 1 in elevation and the mountain biome between 3 and 5 -- barely a mountain, closer to a hill. And as for a 3x3 embark, well, I'm already in that and I still hit 30 FPS by the time I have 100 dwarves despite having a completely modern PC (Intel i7 processor).
There has to be some way to lower the amount of z-levels of rock. The save that inspired this search had a mere 60 levels of mineable rock compared to my current of almost 200 and it played smooth as butter 100 FPS with 80 dwarves on my computer. It was the same size embark (3x3) with all five cavern levels plus a volcano on the surface, too. The only difference I could note was that this save used a different tile set and had significantly fewer z-levels of rock.
Hmm... I've never used a tileset, so I'm not sure if that would change anything, but it might?
Are there any major differences in fort design? Bottlenecks in high-traffic areas can grind things down. Pathing in general eats resources; speaking of, were you dealing with the same animal populations? Loose animals do bad, bad things to FPS.
Major differences in fort design? Well, there was one -- I plan the entire fort out and then carve it out piece by piece, so by the time I had 80 dwarves I'd already carved out about 80% of the total fortress. The fort in this save was smaller, more compact. In terms of bottlenecks, he had a lot of one tile up/down stairs running through the center of his fort, four of them in the corners of a 4x4 area to be specific, while my fort was designed to have a huge central pit with ramps all over it and workshops radiating out from the center; travel time from any one part of the fort to another was crazy low because to get from any one place to the other you just walked up and down the pit. That's kind of an odd design, I know, and it was admittedly a bit experimental and could have caused the lag, but I've experienced this same kind of speed on all previous forts of mine as well (including the massive amount of z-levels). As for animals, I definitely had more of them, but except for the dogs and cats they were all chained or caged. His fort had some loose cats (living in the jungle they're the lesser of two evils, the other evil being vermin, vermin everywhere) but no loose dogs, and all of his livestock animals were either chained or caged as well.
I'm trying out Phoebus' tileset instead of Mayday's for this fort and unless I choose the embark point next to that terrifying ocean I'll be in a very low-lying area. Speaking of which, which embark point would you guys go for?
Embark #1 - Untamed Wilds with minerals
Located on a brook ten tiles south of a goblin fortress, one tile west of a volcano, at a spot where a region with a sedimentary layer runs into the volcanic region with igneous extrusive layers.
Pros:
- Unique spread of minerals; all four layers are well represented.
- Low elevation, hopefully means low amount of z-levels.
- Right next to a volcano so a higher chance of a magma pipe.
- Untamed wilds forest and mountain biome for excellent variety of tamable creatures.
- Sand and no aquifer, heavily forested and thick vegetation.
- Relatively close to a goblin fortress.
Cons:
- No granite, so no bronze.
- Cliffs map says the area is pretty much flat.
- Feels kinda boring, kinda uninspiring.
- Only flux is a single layer of marble on the bottom of the forest biome; likely to share a room with a cavern, so there won't be much to go around.
Embark #2 - Terrifying Ocean
An untamed wilds temperate shrubland with high cliffs overlooking a terrifying ocean. No aquifer on land, but the ocean biomes have aquifers (not surprising). Lots of sand, limestone layer on land, and both ocean biomes have sedimentary layers with aquifers.
Pros:
- Its terrifying, and its an ocean. I've done neither before, and new things rock.
- Untamed wilds for good tamable creatures.
- Tons of sand.
- A medium spread of minerals; lots of different layers, but most of them are igneous intrusive or metamorphic and are mostly useless.
- Sheer cliffs looking out into the sea makes for a cool concept.
Cons:
- No fresh water, will have to desalinate and that'll be a pain.
- No source of copper except tetrahedrite.
- Nearest goblin fort is a long, long ways away. The terrifying might make up for that, but if it doesn't it could be a boring game.
- Elevation is relatively high, the opposite of what I'm trying to test here.
Embark #3 - Advanced Guard fortress
Situated in the south straddling a brook, a tropical freshwater marsh and a mountain biome (all wilderness, unfortunately) on low elevation but massive local cliffs and, oh yeah, exactly one tile away from a goblin fortress.
Pros:
- Adjacent to a goblin fortress. Their arrows will blot out the sun. Definitely a military challenge.
- Both biomes have sedimentary layers. Lots of granite and marble as well. Great mix of minerals, although no igneous extrusive layers.
- Low elevation, but soaring cliffs. Don't ask me how that worked out.
- Never played in a marsh before.
- No aquifer.
Cons:
- No sand.
- Not untamed wilds, so I don't expect much from the wildlife.
- Wood will be a little sparse.
Edit: A fourth spot appears!
Embark #4 - Lake Placid. Temperate untamed wilds freshwater swamp bordering a terrifying cold freshwater lake.
Pros:
- Never played on a swamp nor a lake before, would be interesting.
- No aquifer, but plenty of water.
- Untamed wilds for interesting creatures (although wiki says swamps with it just means slugs and snailmen, which would be bleh).
- Terrifying lake, so woo undead fish!
- Chert for a sedimentary layer, marble for flux.
- Five tiles away from a goblin fortress, so the sieges should be intense.
Cons:
- No granite for bronze.
- No sand, so no glass industry.
- Not a big fan of cold climates, but at least it's not freezing.