Someone (and it's unsure who, as they left no byline) recently decided to run some benchmarks against the three major Web application development frameworks, Ruby on Rails, Django and Symfony.
Firstly, they developed a simple application in all three frameworks that tested similar functions such as basic database functionality, reloading pages, and so forth. They tested the applications with 50 concurrent virtual users and 150 concurrent virtual users on a dual Xeon 3.2GHz server with 2 gigabytes of RAM, and produced some basic statistics for the results.
The testing, however, appeared to be flawed, with the tester admitting that in the 150 user test with Symfony, most requests returned with a 500 Internal Server Error. Their main set of successful results, however, shows that Rails proved significantly faster than Symfony, but Django proved faster still. They also demonstrated that not using a PHP accelerator significantly slowed down the already slow Symfony (a good counterpoint to those PHP programmers who claim their language is the fastest.. it's how you use it that counts!). 10 Mongrel processes also seemed to just outperform a lighttpd-based FastCGI configuration.