Since the industry has seen a growth in distribution of mobile arm architecture products ( i.e. iphone, ipad, android products), there has been an explosion of server side frameworks and software that promises to feast the unending desire of these little buggers to consume real-time content everywhere they go.
Maciej has performed excellent benchmark testing between Apache/PHP and Node.js, which can be found at: http://zgadzaj.com/benchmarking-nodejs-basic-performance-tests-against-apache-php
Do keep in mind he is using the prefork MPM that gets shipped with Ubuntu, which is the slowest, other mpm make use of threads and events rather than processes and hence are faster and more scalable. In our experience PHP-FPM with NGINX can really work wonders.