Been reading a lot here, and I think I am going to switch my forum from PHPBB to Vbulletin. I've read a few comments about the vunerability especially in large forums....what do you consider a large forum?
For a forum on running DOS 6.1 on MAC OS 8, I'd say 2 members would be big. Otherwise it would depend and be related to your server's capabilities. That Gaia Online forum runs on 120 servers so it runs as smooth as a forum that has 3 million fewer members. They run PHPBB, other in absolute numbers HUGE forums run VB. Either should be able to cope. But like I saidit depends on your hardware.
I've consider a large forum 300+ members and/or 3-5,000 posts. I highly recommend switching to vBulletin if you think it's worth the switch. I've bought multiple copies of vBulletin already and I love the interface and the structure of it. Easy to plug and play with it. Good themes too ( Free ones at vbulletin.org)
A forum, that when you close the window for 5 minutes to work and come back. 400 new threads have started. That happens here a lot
I consider a large forum one that that peaks with 50+ registered users at least once every single day. Somewhere betwen 50-100, you are forced to go with a dedicated server.
To me it is always the amount of users online at the same time, once you get over 250 users online 24/7 you got it going on for sure! The problem forum owners face is the fact that most of their members have forums today and everyone is going after the other guys members, many times using tactics that are sad and blatant to high jack members!
I do agree that, for the most part, a large forum is one that always maintains 50+ members online at once, but that's not all there is to it. You also need to take post numbers into account also...A forum that has collected 1,000,000 posts could have died out and only has 20 members online at once. The members online does not suggest it is a large forum, but the amount of posts sure does....so I think it's a little bit of both.
See big-boards.com For them a "big board" is a board with more than 500,000 posts, which seems to be a reasonable mark for a large forum.
I have switched from phpbb to vb in minutes. My forum had around 600 members at that time with 5000+ posts.
For me 10k+ members is large..normally those sites are near the 500k posts anyways to be in big-boards list. I hope to get a site in there this year. I sysadmin for a site that's closing in on top 500.
the number of registered members is rather irrelavant IMO, it's the number of active members that matters.
I seen lame sites with only 250 members yet 100k+ posts. Sorry but members mean more eyeballs which translates into more revenue. A site I own has only 700 members (less than 100 active I bet) and over 50k posts. I run the same banner spots as my site with 200k posts. Now doing the math you would think I could make 25% of their revenue. However I don't. I make less than 5%. So member count very much matters but it should be in correlation to activity.
A large forum could be 100 active members, or it could be 5000 members with only a few active ones. It really depends on how many of those members are active, and not just registered users.