I posted full details about this problem in this thread, but I could probably use some additional feedback here.

Basically, I have a forum around 400,000 posts and 100-200 average users online. Dedicated database server with 512mb ram. Nothing but MySQL being served from that. 512mb should be plenty seeing as thedieselstop runs on 384mb of ram and their single forum searches take .5-2 seconds. They have all forum searches disabled.

My forum runs great EXCEPT for searches. All forum searches, all posts take 30-70 seconds, which is unbearable.

Single forum searches take 5-10 seconds, which is also unbearable since with 150 users online, there are times when 2-5 people are searching at the same time and the entire forum comes to a grinding halt until those processes are done.

My.cnf has been tweaked... all details on that are in the post linked above.

Is anybody running a forum over 300k posts with all forum searching enabled?

I've found several sites with a lot of users online, but only 20-30k posts... which is hardly a comparison. At the same time I've seen forums with 1-million+ posts but with all forum searches disabled (thedieselstop being an example).

There's certainly something amiss since our single forum searches should be taking a second or less in forums with 20-40k posts. As I said, they're taking 5-10 seconds.

Thanks for any insight!

We have 6.41, the searches enabled, with 900,000 posts, but we have a double processor athlon 2.3 gig and 3 gig RAM, which should make quite some difference.