@telmarina Letting MCCC manage your population ideally shouldn't be an issue if you keep EA's culling system, including relationship culling, and population limits. Both are designed to default to what your computer can probably handle. Overriding those default limits is where you get more problems. The more interations/relationships/Sims/objects the game has to calculate, the more lag you can get. Similarly with visuals: the more detail the game has to calculate, the more potential lag.