Forum Large Number of Forums = Poor Performance?
 

I have an installation of vBulletin forum that has about 3000 subforums under one board and the forum averages about 2,000 users online at a time. I don't show any subforums on the board index and I have the quick nav disabled, but my board takes about 3-5 seconds to load. When I deleted most of those subforums and rebuilt the forum info, loading was almost instant. Can anyone confirm if this is a problem with vBulletin 4?