If you’ve been following Peter’s weekly digest posts, you can see we’re working hard on the next release of WordPress. One of the main efforts in 2.4 is improving performance. I’ve been busy with xdebug and kcachegrind finding places where we can speed things up. If you have a theme that uses widgets or custom header images, 2.4 should be a good bit faster for you. We found a couple of time-wasting bottlenecks in those areas that are now gone. One scenario was burning up 10% of the total page load time. We reduced that to a fraction of a percent. That’s a nice savings. We’ve also been tweaking the filter/action system to make it as fast as possible. The filter and action hooks are fired off many times per page load so even little savings add up.
Caching is also getting attention in 2.4. We’ve had the object cache for awhile now, but there were some areas of WP where it wasn’t being used. The object cache now caches quite a bit more stuff. If you are using the APC, XCache, or memcached backends for the WP object cache, you will notice a few less database queries in 2.4. We also have an Advanced Caching plugin in the works that caches even more stuff. On many page loads you will see zero queries. If you have a fast cache and want to ease DB load as much as possible, this plugin might be for you.