I originally put this tutorial together for century_eyes, but I thought I'd go ahead and repost it here in case anyone else could get some use out of it.

If you primarily use package files for your custom content and have noticed increased load times and/or lag in your game, follow this tutorial to combine your CC into fewer, larger packages to fix the problem.

( Combining packages... )

You can combine combined packages, and it's ok to add more things to your combined packages at a later date.

I'd suggest instead of making one huge package of all your CC to have four or five, only because when I tried to make a single package things started to blow up. I've got Objects, CAS (hair, clothes, makeup), Patterns, and my own crap as their own packages.

I've not combined Default Replacements (never sure if I'll switch those out or something), my hacks, and AM/story progression.

Very easy, and holy shit it makes a huge difference. My game now loads as quickly as it did before I had any CC in it, and no longer lags at all.

This is the original thread on MATY. Anach has offered up this additional information, which is very useful:

1. If you have a merged a mod and wish to update it with a newer version, you will need to re-merge the entire package, or you will usually experience game breakages.

2. The game imposes a limit of 200MB on its own merged packages (dbc), however a package can be anysize, and the only limitation is processing time (larger takes longer) and filesystem limits.

3. Try to keep your total number of mod packages under 100.

4. You can also remove ICON type files (junk files used by sims3pack) and "THUM" (thumbnails) if you wish the game to generate its own thumbnails rather than use the ones provided in the package.

(Originally figured out by someone Anach on MATY.)