title: Can the thread per request model be faster than non-blocking I/O?
body: <p>I remember 2 or 3 years ago reading a couple articles where people claimed that modern threading libraries were getting so good that thread-per-request servers would not only be easier to write than non-blocking servers but that they'd be faster, too. I believe this was even demonstrated in Java with a JVM that mapped Java threads to pthreads (i.e. the Java nio overhead was more than the context-switching overhead).</p>
  
  <p>But now I see all the "cutting edge" servers use asynchronous libraries (Java nio, epoll, even node.js). Does this mean that async won?</p>