Why is the overhead of all the PHP frameworks so high? Is it because they have to evaluate all the framework code per request? The difference between raw PHP and symfony2 is massive!
I think it's because raw PHP doesn't do anything. You're literally benchmarking how fast you can do nothing. As soon as you add any kind of logic the number goes way down. It's like saying the performance of adding 4 numbers is a massive difference from the performance of adding 2 numbers.