Alldrupalthemes.com did a performance comparision between Joomla 1.5 & Drupal 6.1. As the author of the post infers, the numbers collected may not mean much to the user in the "real world" and limitations in the test results should be noted. Nevertheless, numbers that compare Drupal and Joomla performance are always interesting.
The conclusions drawn from the results are:
- Drupal is significantly faster than Joomla in all 4 setups
- Drupal cuts down pageload time by ~74% when caching is enabled on the fresh install and ~86% with the more populated setup
- Joomla cuts down pageload time by ~23% on the fresh install and ~20% on the more populated setup
These numbers are interesting and I bet the study pulls in a lot of visitors for All Drupal Themes. Not only are Drupal and Joomla users interested in these type of posts, but so are potential users shopping around the first time for a CMS. As always, you should judge a CMS by what it does for you and not what it does for others.