My question was: Why is the Javascript version 20 times faster on the same machine. I mean.. 20 is a really big factor.
Edit : Think about that : web browser are always on the cutting edge of javascript performance with the ton of javascript libraries that keep popping out each day. Everytime a new browser comes out, tons of bloggers test the javascript speed of those browsers so there is a lot of work going into optimizing javascript to make it as lightning-fast as possible.
On the other hand, PHP hasn't been pushed like that towards compile-time optimization so that's why Javascript can sometimes beat PHP in terms of speed tests.