Understanding Global Module Caching in Joomla

Joomla 2.5 has reached its end of life as for 12/31/2014. Please be advised this may be a security risk to your website. You can view more information about the end of life here.

Enabling caching in Joomla 2.5 is a great way to speed up page load times and reduce server load. While there are several articles already on the web about Joomla 2.5 caching, they fail to provide clarity, and they all generally repeat the same information. In this article, we hope to answer common questions regarding the Global Configuration >> System >> Cache Settings.

**Note: This guide also applies to Joomla 3.

Using Tests to Understand Global Caching

In our testing, we created a simple module called mod_last_cache. This module uses the php time function and prints the current time to the screen. The idea being that if cached content is being served, you will see an older time on the page. If cached content was not being served, you would see the actual time on the page.

We also tested using two different computers. Each unique computer is referred to as User 1 and User 2 in the raw data table listed further below in this article.

RESULTS

After running our tests, we came to the following conclusions:

Raw Results

Items in green represent cached content being shown. Items in red represents non cached content being shown.