WB :) Keep in mind Step 4 of that link is false info. There's no way to boost how much RAM a 32-bit program such as Sims 3 can use. People will claim they followed that step and think that it helps but it's simply not possible. Limiting framerate is very important though so don't skip that. ;) I recommend keeping the in-game setting High Detail Lots low... Doesn't matter what computer someone has, the game just doesn't like having to render every nearby lot if it doesn't have to.
I believe if you're on patch 1.69, Save Cleaner 2.2 won't work. You might want to check out the NRaas page:
Tips For Better Game Performance if you haven't already.