We used a single 500 MHz web server at the ReactOS.org project and it handled the slashdot/reddit effect til ~2008. Slashdot.org was the 8 biggest website in th

We used a single 500 MHz web server at the ReactOS.org project and it handled the slashdot/reddit effect til ~2008. Slashdot.org was the 8 biggest website in the world back in 2005 (Alexa ranking). I coded a novel CMS in PHP that generated hundreds of static pages in 2-3 seconds. Our open source project team as well as dozens of translators (27 languages) used the RosCMS ajax-based interface to edit the content. Back then ajax was little known and GMail used iFrames instead of ajax. PHP based MediaWiki, phpBB, bugzilla also run on the same server, and all used our central logon system. That's the old version of the website: http://old.reactos.org http://old.reactos.org On a recent project my social website served thousands of concurrent requests on a notebook class hardware with a single CPU. It uses nginx and HHVM (Facebook's PHP JIT VM). And @vidarth is right that people usually don't know how many objects they create. But if you tend to care about speed you better should be careful. The same goes for database access, raw optimised SQL with good indexes fly.