@eugenmayer you are quite wrong, but this is not the place to discuss about drupal and drush, just make me reply that the “perfect” benchmark to me it’s something that just stress the filesystem, the clear cache process involves 99% of its time on database and cpu. The “perfect” benchmark it’s maybe a drush script which trigger just the registry rebuild process io-wait intensive + autoloader bootstrap and/or config files reload (D8), any database process should be involved to have a consistent test case.