Brief comparison of Drupal 6, Drupal 7 and Pressflow with the help of XHprof

In order to see the average data of all the three XHprof launches, we'll create total.php file in the directory of our html-interface that will parse identificators of launches and will redirect us to the actual average report:

php
if (!$_GET['namespace']) { 
  exit('there is no namespace in $_GET parameter.'); 
} 

$namespace = (string)$_GET['namespace']; 
$path = ini_get('xhprof.output_dir'); 
$dir  = dir($path); 
$pattern = "/^([0-9a-z]{13})\.{$namespace}$/i"; 
while ($file = $dir->read()) { 
  if (preg_match($pattern, $file, $matches)) { 
    $files[] = $matches[1]; 
  } 
} 

header(sprintf('Location: /xhprof_html?source=%s&run=%s', $namespace, implode(',', (array)$files)));

Now when we go to <xhprof_domain>/total.php?namespace=<name> we'll be given information about all XHprof launches for the specific namespace.

We've got the following results in our test (clickable):

             Drupal 6                                    Drupal 7                                Pressflow

Screeshots (clickable) of graphic interface are given below. The whole thing looks very complicated yet unlikely to render any practical use but it looks nice, like an insight into the inner scheme of Drupal work =)

             Drupal 6                                      Drupal 7                               PressFlow

It's better to use the data of graphic interface in case of profiling of small part of code.

Summary

As we see Pressflow showed the best results (average time of page generation is 109 milliseconds), on the second place almost without breakaway is Drupal 6.20 (114 milliseconds), and on the far third place is Drupal 7.0 (238 msec).

Though in reality Pressflow will show much better results in comparison with basic Drupal.

Another interesting point is that there are no "critical" points in Drupal 7.0 (i.e. red elements are absent).

And yes, experiment was repeated three times on different servers and Drupal 7 was behind with more than double breakaway...