When I say it compares in performance to other systems I mean other high level more-than-a-socket systems like XMPP servers, which I spent a lot of years benchmarking and optimizing. Of course to-the-metal binary packet systems will be much faster as you're doing the buffer management and choosing your copies wisely.

It would be super-awesome to see a profile of node.js when you run this test to see where the CPU is going. Is it something low level like the string parsing, buffer copying, socket writing, or maybe something higher level like some inefficient algorithm somewhere. As I read below that socket.io is focusing on performance now, I guess we'll know soon. :)