Joomla is a popular CMS that is highly extensible and customizable. The  following are suggestions for optimizing your Joomla installation and reducing  the CPU consumption of this script. These suggestions are not guaranteed fixes  to bring a site to normal CPU consumption, but they will drastically reduce the  amount of CPU consumed by a Joomla installation.

 

Enable Caching

This is probably the most important optimization tip. You can lessen the  footprint of your site on the server noticeably by having caching enabled at all  times. Please remember that we do NOT recommend any form of OPcode caching on  VPS accounts of any type due to shared memory limitations; in addition, this  type of caching is not allowed on shared accounts of any form.

 

Avoid Image-Heavy Templates

Some templates may look nice, but they can use up to 70 images per page  request, each of which generates an HTTP connection to the server. When traffic  to your site becomes high, you will end up consuming enough CPU to cause the  server's load to rise. You should consider clean template styles instead of  image heavy templates.

 

Disable Gzip Compression

The CPU has to work harder to compress each of your pages before it sends it  out. If you have Gzip compression enabled, an extra overhead is added to each  page request. The speed gained by compression is offset by the CPU time  requirement, resulting in higher load with no actual gain in performance.

 

Use Components Sparingly

Many components are heavy CPU consumers and will cause your site to raise the  server's load. Make sure you're only using the minimum amount of components that  are necessary to the operation of your site. Disable or remove any components  that you are not actively using.

 

Avoid Statistics Components

These use a lot of SQL queries to constantly update and display your site  statistics. This results in increased CPU usage and causes additional IOwait.  Use Awstats or Google Analytics instead to track users.

 

Optimize Forums

If you are using a forum bridge/extension such as FireBoard or something  similar, make sure to require visitors to register before they are allowed to  search and post. Also, employ captchas to reduce spammers on your board.