fastcgi_finish_request

Call fastcgi_finish_request() on shutdown. This is able to speed up WordPress on servers where PHP is not tied to the webserver, like Nginx and certain configurations of Apache. If this is not the case this plugin will not do anything.

You can read more about fastcgi_finish_request() on the php documentation page: http://php.net/manual/en/function.fastcgi-finish-request.php