Significant performance improvements
Plone has a strong track record in performance, but the web is busier than ever and there's never time to rest on our laurels. Performance tuning was a major focus of Plone 4, and we're proud to show you the results. Plone 4 is about twice as fast as Plone 3 was under high loads, and up to four times faster than Plone 2.5. It also uses much less memory than previous releases, which lets you squeeze even more performance out of a given amount of hardware.
Here's a quick comparison of how much faster Plone 4 is at common tasks:

We also focused on improving performance when your site has lots of simultaneous users. Here's how much Plone 4 has improved compared to previous releases:

Methodology: Using the Funkload suite with an increasing number of concurrent requests over time. All numbers relative to Plone 2.5 with Plone 2.5 as the baseline — i.e. 100% means twice as fast as Plone 2.5.
Plone's also faster than many of its open-source competitors. Here's a simple comparison of some well-known open source CMSes from the lower end of the spectrum that are usually considered decent performers. Higher bars are faster.

Note: all of these systems ship with caching disabled by default and that is how we tested. Appropriate caching can significantly improve the performance of all systems by 100× or more. But at that point, you're comparing the performance of your caching proxy or database caching layer, not the CMS itself — which is an important distinction.
Bottom line: Plone 4 is fast. We think you'll like it.

