umm. I run a server with over 74 mods, including the new redpower and mystcraft, the players have gone retarded and I have over 150 worlds, and they are full of marble.(and other stuff, i have at least 8-10 mods with a lot of terrain gen. quite a few dense ore cave worlds also. This has to be a config issue, I wouldn't take away one of the cooler terrain gen features over that. I love cave worlds . Its a dedicated server too, although to slap the moniker 'modern' on it, will only last a few months, and then the new 'modern' is in. (fwiw its an older Xeon series).But even still, no crashes from terrain gen.