Drupal is the faster one. I looked at both Joomla vs Drupal and chose Drupal because it was easier to learn too.
I think that wordpress runs fast , also and Joomla runs fast , about Drupal i have not idea. P.S : Also and Blogger run fast !
When Drupal is configured well its faster then Joomla. How much is that difference? Well I dont exactly know but I know you wont notice the difference (or at least not much) at websites with just a few visitors. If you have a website with lots of anonymous traffic then I would recommend a configured Drupal. This is purely from the point of view of speed, personally my favorite systems are Wordpress and Drupal..
Drupal is a good CMS, as is Joomla, I have tried both of those. While PHPFusion doesn't have some of the advanced features that Drupal or Joomla offer it does have roles, you can restrict administrators roles to just the features you want them to edit and control, you can also assign members to groups so you can have content for some members but not others, It also has a great deal more templates for your site than I found for Drupal or Joomla, I also think it lays out better. When it comes about the running of websites, though dependent on web servers, but obviously Wordpress is an ace. Not just because the platform has some really great code structure and optimized architecture but also because the platform is not for all types of websites , but mostly caters to the websites with blog themes, etc. PHP Framework
WP is faster; but with proper caching Drupal can compete with WP. And of course number of plug in matter. If you think about functionality then Drupal is fastest comparatively; as it is more than a blog.