Ruby on Rails and scalability problem

Hi,

Is ruby slower than PHP.
Is ruby on rails slower than PHP framework like zend framework?
Is ruby on rails slower than ASP.NET?
Is ruby on rails slower than Java?

Can anyone give practical comparison with other languages?

What are the scalability problems with ruby or ruby on rails. Did you
face any problem with ruby or ruby on rails for big projects?

Thank You.

http://www.buildingwebapps.com/articles/6419-can-rails-scale-absolutely

Web frameworks benchmarked - this should help you.

https://github.com/seedifferently/the-great-web-framework-shootout

The fastest car in the world is the Bugatti Veyron Super Sport
according to http://www.thesupercars.org/fastest-cars/fastest-cars-in-the-world-top-10-list/

Yet somehow everyone else (ie those millions who do not drive a
Bugatti Veyron Super Sport) seem to get along just fine with what we
have.

Do you have a specific query or are you just looking for a fight?