Yes you can do the same in PHP by disabling output buffering. You're limited by the web server's concurrency model however. Apache's mod_php only works on the prefork MPM so your concurrency is limited by the number of Apache processes you can spawn (which can be quite bloated because you run the PHP interpreter inside Apache). Another less commonly used but still notable setup is PHP via FastCGI (e.g. when using PHP through Nginx). Here you are limited by the number of PHP-FastCGI processes you spawn.