I wrote this back in June when I was knee deep in attempting to optimize a Drupal 5 website that was receiving a lot of traffic and showing very poor performance. This article is incomplete and I don't really come up with any solid solutions here, but thought this may be of some help nonetheless.

Performance of any site is a concern when you start getting actual traffic. Drupal performance can be even trickier, as it often likes to hog up server resources especially when you have a lot of modules enabled.

Often the issue lies with mySQL. While I like mySQL, configuring for optimal performance doesn't always come easy. One issue that can often occur is a large number of temporary tables being written to disk. What we want is for these tables to be written to memory. A good article which discusses the overhead of mySQL writing to disk can be found here at http://www.mysqlperformanceblog.com/2007/08/16/how-much-overhead-is-caus...

Essentially, it says MEMORY temporary tables can be 10-100 times faster than disk based MyISAM tables . That's quite a difference.

I started two or three weeks ago tweaking our mySQL configuration and performance on a site that was getting 85% or more of it's temp tables written to disk. Today, we're getting between 6-10%. There's still work to do, but the increase has been awesome and very noticeable in the speed of the site.

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