User blog comment:Alex9400/From Sims 3 to Sims Medieval/@comment-26744861-20120105184819

My custom "sandbox" neighbourhood loaded much faster than the shipped neighbourhood as I didn't attach the shopping district/vacations districts etc. in addition to having very few Sims there.

Whatever a new EP/SP/CC object adds is another thing that the game has to load at once for some reason just so that everything in the neighbourhood (including sub-neighbourhoods) is usable, even if you're only playing one family.

The installs for all the TS2 EPs alone is almost 11GB (maybe more, maybe less) and that's without the custom content (which I'm sure is several gigabytes. All that, plus a laptop with an Intel GMA, 2GB of RAM and a load of other stuff running at the same time, TS2 loads pretty slow. :/