Joomla: Optimization

Joomla is a popular free content management system that is reliable and highly customizable. Below are suggestions for optimizing your Joomla installation and reducing the CPU consumption of the Joomla script. Please keep in mind that these suggestions are not guaranteed fixes to bring a site to the normal CPU consumption. However, they will drastically reduce the CPU usage by a Joomla installation.

Enable Caching

This is the most critical optimization tip. You can reduce the footprint of your site on the server by having caching enabled all the time. Please note that any form of OPcode caching on VPS accounts of any type is not allowed due to shared memory limitations. 

Avoid Image-Heavy Templates

Consider using clean template styles instead of image-heavy templates. Some templates may look pretty, but they can use up to 70 images per page request, each of which yields an HTTP connection to the server. When traffic to your website increases, you will end up consuming enough CPU to cause the server's load to rise. 

Disable Gzip Compression

The CPU works harder to compress each of your pages before sending it out. If Gzip compression is enabled, an extra overhead is added to each page request. The speed gained by compression is compensated by the CPU time requirement, which results in a higher load with no effect on performance.

Use Components Sparingly

Many components consume the CPU heavily and cause your site to increase the server's load. Make sure only to use the minimum amount of components necessary to your site's operation. It is highly recommended to disable or remove any components you are not actively using.

Avoid Statistics Components

These use a fair amount of SQL queries to constantly update and display your site statistics, resulting in increased CPU usage and causing additional IOwait. It is best to use Awstats or Google Analytics instead to track users.

Optimize Forums

Requiring visitors to register before they can search and post on your site if you are using a forum bridge/extension such as FireBoard or something similar would help optimize your Joomla website. At the same time, you can employ captchas to prevent spammers on your board.