Culling

Culling removes Sim relationships from your game to keep the total number of sim relationships down. Really short version is that it removes Sims that active sims do not have (much) relationship with. Once a Sim is culled, your sim forgets them completely.

You can protect Sims that you do not actively play from being culled by making sure that they are in the "My households" section of the neighborhood manager. Only Sims in the "Other Households" are fair game for being culled.

And yes, I have it on, though I set the upper limit to "unlimited" and have MCCC set to do the culling rather than letting EA's culling do the job. Playing without culling on, long term, puts you at risk for the save game in question becoming unstable or potentially even completely broken and certainly impacts performance...eventually.

@luthienrising and @Neia have a thread about culling which goes into some more detail as well.

Good call @Terra!

@Chelseadude182, the thread @luthienrising has on the subject is located here: https://forums.thesims.com/en_US/discussion/905991/culling-relationship-culling-decay-current-status/p1

Is culling good for keeping game lagging down? Or is it really just for the convenience of having a lot of questionable relationships? I had a save running for a month with lifespan on Long, and every single townie has remarried some other sim and keep popping out babies.

"UtauIA;c-16892015" wrote:
Is culling good for keeping game lagging down? Or is it really just for the convenience of having a lot of questionable relationships? I had a save running for a month with lifespan on Long, and every single townie has remarried some other sim and keep popping out babies.

It's for performance reason. If you check out the thread I linked in the post above yours, it talks about this.

For me, culling is the game deleting sims to make room for newly generated sims. It also goes into relationships and removes least important ones to keep the performance up.

Sim culling used to be a big issue because it was too aggressive but the devs tuned it and it's not really a problem at the moment. Relationship culling is still a little too pushy for rotational play but not impossible to deal with(out mods).