Yes Charles, that's the board.

Ah - the limit is threads, not posts.. I was obviously confused there.. So, the 5000 number I've seen in the past is not actually an issue for me (yet)..

The number of registered users is way below the threshold of 10K I know, and I see so many other boards with more posts, more members, more active - so the slowing performance of mine is an issue / concern..

Accelerator? PHP installed - I have been running the boards for about 2.5 years - always on a windows server, and never with PHP, and performance has not been an issue in the past - growth has been very steady (10-15% a month) - what will PHP get me? What are the risks? (is it stable? does is play nicely with windows? ??)

Looking at the server performance in detail I see CPU pegged for long periods of time, I/O and memory seems not to be issues..