UBB.threads PHP Forum Software Community Forums Resources and Customizing Admin Zone Any other high post Forums out there?

There are a couple I know of that have a couple million posts and don't prune anything. As numbers grow, it really comes down to your server specs and it being optimized properly, specifically MySQL.

If you have your own server then that's the first thing I'd look at is making sure that MySQL is optimized for your particular server specs. A poorly or untuned MySQL install won't keep up as your numbers continue to grow.