Over the past few weeks I’ve been looking at different solutions to improve the speed of my WordPress websites. The first step was to mirror and redirect the static content to another server (aka Content Delivery Network or CDN). I’m currently using a DreamHost VM, but I may look into using Amazon S3 as well. This is an easy way to save bandwidth, and off-load a web server that is configured for dynamic content (larger and slower). In the case of PHP and WordPress, there are several additional options available to improve local web server performance. I’ll describe the ones I’m currently using, including their expected impact to performance and short-comings. This article deals mainly with the local Apache Httpd and PHP configuration. There are additional infrastructure solutions that can improve performance, like using Nginx servers on the front, Varnish cache servers in the middle, and Apache Httpd on the back-end (for PHP and WordPress). This post is only about optimizing the Apache Httpd back-end. If you’re considering adding a Varnish server in front of Apache Httpd, you should probably avoid caching whole pages in Apache Httpd and leave that to the Varnish servers.