Using the latest version, 2.1.4 here, everything enabled, SWHM. Every time I start up the game, in a few months the game starts lagging quite hard, especially when each day goes by. When paused, the game doesn't lag at all. I reduced my resolution and am playing in windowed mode since the first time it happened, but it doesn't change anything performance wise; the game starts lagging very hard in a few months. Even though the game is using up quite a bit of my RAM, there's still plenty available for the the game to run, and I don't experience the same problem any other mod or vanilla. My GFX card is decent enough as well (Gtx 660 Ti), and I have about 90GB of free hard drive space on the HD i'm saving the game to, so i'm not sure what's causing this problem really. This is making the game barely playable at a reasonable rate, please help.
Also, playing on Ironman, which is the only thing I think could be causing it.
EDIT: Fairly confident that it is in fact Ironman, so anyone reading this shouldn't play with it while using this mod.