my website currently uses vbulletin 4 on a dreamhost VPS, and it's still slow, and gets database errors/timeouts, etc, and stops working at all when i drop the ram below 600mb. im really liking xenforo, but i was wondering if it works well on shared hosting? or, what specs would you recommend (ram, etc) for a VPS? my site currently has 4,000 members, 800 or so active, and about 30-40 online at any given time. thanks!