My last post on how to optimize WordPress covered some general optimization techniques to speed up a website. Reducing HTTP requests, removing wasteful plugins and decreasing file sizes helped quite a bit. Now it’s time to try out page caching.
If you remember, the five things that normally occur for each page are:
- Initialize PHP
- Query the database
- Create the page
- Send the page
- Send additional files
All of the plugins were fairly easy to install. And I discovered during my tests that WP Super Cache, at least at Nearly Free Speech.NET, works just fine with safe mode on.
This graph shows the time it took to load my home page with each of the caching plugins enabled. I have circled the point where I first turned on page caching.
Hyper Cache and WP Super Cache both performed well. W3 Total Cache seemed to struggle. It does more than page caching, like reformatting files to save space, but clearly slowed things down.
WP Super Cache has a few advantages over Hyper Cache:
- It supports browser caching better
- It doesn’t need to load PHP
- It checks for security problems and suggests fixes
So I am now a happy WP Super Cache user.
UPDATE Dec 2009:
After a few days, I started having issues with WP Super Cache and switched back to Hyper Cache. You can see how the irregularities went away. I’ve been using Hyper Cache for almost a week now, and things have remained stable.
After being contacted by the author of the W3 Total Cache plugin, I’ve agreed to give it another try. I turned off all the settings except for “disk enhanced” page caching. I’ll update the article again in a few days.
UPDATE Jan 2010:
After looking into things a bit more, my results are still showing Hyper Cache to be faster than W3 Total Cache. However, when I test using the curl command line tool from home, it seems that both plugins are about the same speed. My web hosting company uses a network-level reverse proxy and a few other caching tricks that eliminate the need for some of the features provided by these types of plugins. I’m not sure what’s going on here, but will be sticking with Hyper Cache for now since it appears to work better with my particular situation.
I do like that W3 Total Cache handles page compression properly. I could not get page compression to work with Hyper Cache and had to turn it off. I’d recommend you try all three plugins and measure which works best for you.
UPDATE Apr 2010:
I’ve been having some troubles with Hyper Cache recently. Page redirects were working properly in Firefox, but not in Safari. I tried a new caching plugin I hadn’t heard of before: Quick Cache. Redirects are now working in both browsers. After a week of using Quick Cache, it’s performance is very good. I’ve decided to stick with it.