a question about zend framework's speed

[hzqij1978]

I am a newer of Zend Framework, i write a program to test the speed of
Zend Framework, code like this:

/var/www/htdocs/index.php
<?php
require_once 'Zend.php';
require_once 'Zend/Controller/Front.php';

Zend_Controller_Front::run('/var/www/app/controllers');
?>

/var/www/app/controllers/IndexController.php
<?php
require_once 'Zend/Controller/Action.php';

class IndexController extends Zend_Controller_Action
{
public function indexAction()
{
echo 'hello, world!';
}
}
?>

my .htaccess file is:
RewriteEngine on
RewriteRule !\.(js|ico|gif|jpg|png|css)$ index.php
php_value include_path "/var/www/lib/ZendFramework/library"

i use "ab -c 5 -n 1000 http://localhost/", it show me 32.27
requests/sec, but if i write a php program direct echo 'hello, world',
it can handle 2004.32 requests/sec.

how can i Optimizate my program of zend framework version?

thanks