"Fast" is not a question of a framework, but of the coder.
You can code with any framework and cache the result.
Even dynamic pages used to prevent unauthorized users from accessing it can be made in a static way.
I'm currently coding a project meant to serve up to 1 million hits per hour (280 hits/second) in a "hot" environment (cache filled). This is done with the Zend Framework, producing a lot of static files (even the ACL and Auth-Things can be done static).
If this works as expected, I would like to send Jon an example, maybe he can make a Zend Cast out of this.
But If you ask, if plain PHP is much faster - you know the answer already.
It's up to you how fast your apps are.