The Avent Labs blog has done some basic benchmarking on some of the more popular PHP frameworks out there today. The post includes the tools they used and the full results.
In response to Wil's comment regarding the PHP framework performance comparisons I made in my previous post, I have decided to post the results I got. My decision not post them initially was due to the benchmarks not being done in complete isolation (a separate client and server machine) but the scores relative to each should still be accurate and that's what I am testing for.
He used a machine with a 1.8Ghz sempron chip (running Ubuntu) to run the tests through httperf. His method involved creating the same sort of "hello world" sort of controller to gauge the framework's performance and a baseline procedural version of the same as a guide. His full results are available as a tar file and as a zip archive.