Ironman2#40358
The lagging and the freezing every few seconds that's been introduced in IP has 1 major cause.
You know the game constantly spawns random Sims in random places throughout the World.
Well, sometimes Sims spawn in places (routable places, otherwise Sims wouldn't be spawned there) that are completely surrounded by unroutable terrain, so those Sims spawned in such places can't go anywhere and they are stuck. Stuck Sims like that cause lag as they keep trying to escape but aren't able to.
The more stuck Sims there are in a world, the more lag that causes, which may cause animations, Sims, or other things in the game to occasionally freeze every now and then. In severe cases, the game may freeze every few seconds, for up to a few seconds.
Needless to say, the amount of stuck Sims in a world continues to add up as time progresses, causing the lag to become worse over time.
In the first place, I wonder why there are any routable places, but which are totally surrounded by unroutable terrain, at all, in EA-made worlds. It makes no sense why there are places where Sims can spawn but are surrounded on all sides by unroutable terrain so those Sims can't go anywhere and get stuck. Leave it to EA to make mistakes like that.
In the IP World (Isla Paradiso), there are many such places where Sims can get stuck, way more than in any other World so far it seems, which would be the major cause of the lagging and freezing issues in the IP World.