One of my WordPress blogs was crushing my hosting service causing me to migrate to a new host. Even after migrating to the new host, my host was throttling my CPU usage. This forced me to really dig in and find out how to Optimize WordPress to avoid CPU Throttling and reduce load!

I run a pretty vanilla WordPress blog, so I knew it had to be plugins causing me pain.

I installed P3 (Plugin Performance Profiler) to help see how plugins were impacting my site and load. It showed me the plugins with the heaviest overhead. Even with this awesome plugin, it was still a game of disable, test, re-enable, test again. Blah, what a headache.

Many people swear by W3 Total Cache, but it just wasn’t doing much for me, I’m sure it wasn’t hurting, but I saw much better results by using WP Super Cache. WP Super Cache was a game changer, I could see the blog’s load time speed way up, but I was still being throttled.

Edit 12/20/2013:
I’m back on W3 Total Cache, mostly because I opted to use MaxCDN for CDN to speed up my site and reduce the load on my server.

I also have some widgets that show the current list of the 10 most popular posts, and it’s shown on every page. I then added WP Widget Cache. WP Widget Cache also helped quite a bit, since it would cache my widgets. If anything gets weird, I can clear the cache for any widget I need to. This plugin really helped my blog.

Use Google Libraries Plugin

This adds the Google Libraries plugin to your site. It will reduce your page load time. The Google Libraries are served from Google’s servers, and since it’s from Google, it’s compressed and always up to date.

Many of the large sites use these Google Libraries, so it there’s a good chance that your users will already have it cached in their browser, even on the first visit your site.

You really should add this plugin: http://wordpress.org/extend/plugins/use-google-libraries/

Related Posts Plugins

To be honest, I didn’t even consider the related post plugins, until I stumbled onto some support posts about how these plugins can cause serious load issues.

P3 (Plugin Performance Profiler) showed that WordPress Related Posts, was having a huge impact on my site.

This is a great plugin and is pretty much the standard for Related Posts, plugins, but once my blog got more popular, and more views, the related posts plug was really really hurting me. I know others use it without any problems, so I’m not sure what was different about my setup.

I switched to Efficient Related Posts after reading:

Basically, current related post plugins build the list of related posts on the fly when the user needs to view it. Since blogs tend to be viewed far more often than they are updated (often hundreds of times more often), these queries are run way more times than they need to be. This not only wastes CPU cycles, but if the queries are slow (which they will be if you have 1000s of posts and tags) then the user gets a poor experience from slow page loads.
Efficient Related Posts moves all this effort into the admin section, finding related posts when a post is saved rather than when the user views it. The advantage is that if the query is slow it happens less often and the post writer is the one that waits rather than the user (which I think is WAY better). 

Keep in mind that Efficient Related Posts, isn’t as fancy, but at this point, I had no choice, unless I wanted to move from shared hosting to a dedicated server host, which can be very pricey!

Popular Posts Plugins and Widget
I also removed my popular post plugin (and widget). It was doing some queries and sorting every time someone viewed my page, for every view. I really liked this, but I’m doing similar stuff with Jetpack now, so it’s not a total loss.

I also disable extensions that I wasn’t using, such as Jetpack, which was having a large impact, even though I wasn’t using it.

Edit 12/20/2013:
I re-enabled Jetpack, so I could take advantage of it’s site statistics and commenting system. The comment system, since it leverages social network authentication, has reduced my comment SPAM by a 100-fold. I used to get 1000’s of Spam Comments per day, but I have had 2 since I’ve activated the Jetpack comment plugin.

Lazy Load was helpful, until I started using the paid caching service, CloudFlare, they do a similar technique and both of them together was a little bit weird. Lazy Load worked fine with the free version of CloudFlare, because they don’t include that feature in their free version.

Optimize DB is handy to keep the DB clean and efficient without running MySQL commands. Good housekeeping is really important to blog health and speed.

My blog now loads in about 3 seconds flat, and you can see, in the image above, that once I found the right wordpress plugins for the job, I was able to Optimize WordPress to avoid CPU Throttling and reduce load!

If you want an objective view of your blog or website’s speed: