I believe the more the database of this forum grows bigger and bigger the slower the forum will become. As I see it, the admins of this forum should optimize the mysql databases by deleting all posts with dead links (there must be thousands of them!) and impose more strict rules on posting and replying. For example, it is unnecessary for anyone to quote someone's whole message body with its pic previews--for this not only slows down the browsing but it also adds load on both the bandwidth and the database.
As I also see it, the board itself has to be updated to the latest version of the phpbb forum software. There are also several phpbb hacks that are not implemented here. This one, for example:
http://www.phpbbhacks.com/download/8283 (sets the minimum posts required to download attachments) is but one of so many ways to save bandwidth.
The best solution, however, for this great forum is to convert this forum into the far better MyBB forum software
http://www.mybboard.net/. I'll be most willing to offer help in every possible way.
Cheers