Well, you should stick to the wiki for tips to optimize fps and stay in 3x3 sites. You must be doing something wrong because you fps issues are similar to pathfinding issues (by walling up necessary paths like HFS causes massive fps drop) or massive fluid movement. I have never seen my desktop's processor drop below 30 fps even when rerouting a river. 4000 fps does not drop to 10 for nothing.
Because even on my amd sempron I never hit 0 fps besides the time I collapsed a fort on itself. I always stuck to small maps, large ones with water rendered constant 5fps.
Ohh... I am sure there are pathfinding issues.. half the times sieges just stand on the edge of my map even though the gates to my fort never close anymore... (10 legendary archers and traps provide enough defense) But just because you brush them off as "Pathfinding issues" does not mean they are not broken!
There is an issue with large dug out area....
There is an issue with pathfinding if a route is not avilible...
There is an issue with ramp designation...
There is an issue with smoothing jobs....
There is an issue with stone in the stocks menu....
There is an issue with fluids movement....
There is an issue with heat tracking...
There is an issue with dwarves in the same tile as another...
There is an issue with animals and dwarves colliding...
There is an issue with animals on restraints....
There is an issue with stockpiles when you designate it and remove part of it, and replace that area with a separate stockpile.
There is an issue with Large area's of tree's designated for harvest....
There is an issue with large area's of plants set to be gathered...
There is an issue with restricted tiles being used very often....
You know what all those issues have in common?
They all slow the game down!
Just because they have been identified does not mean the game should have them...
I am NOT doing anything wrong... I am playing the game how it was meant to be played.... IE in any manner I want to.
And quit whining that my embark is too big.. 3x3 IS NOT too big... at least it shouldn't be when the recommended size is 6x6! If it is really too big the game should make finer grained embark tiles so we can cover more biomes in less area.