I don't believe it's just that. One of the coolest features which if it is used properly actually speeds up the response times of a normal blocking php script /

I don't believe it's just that. One of the coolest features which if it is used properly actually speeds up the response times of a normal blocking php script /app flow is the as async feature: http://docs.hhvm.com/manual/en/hack.async.php http://docs.hhvm.com/manual/en/hack.async.php.