node.js performance with zeromq vs. Python vs. Java

I've written a simple echo request/reply test for zeromq using node.js, Python, and Java. The code runs a loop of 100K requests. The platform is a 5yo MacBook Pro with 2 cores and 3G of RAM running Snow Leopard.

node.js is consistently an order of magnitude slower than the other two platforms.

Java: real 0m18.823s user 0m2.735s sys 0m6.042s

Python: real 0m18.600s user 0m2.656s sys 0m5.857s

node.js: real 3m19.034s user 2m43.460s sys 0m24.668s

Interestingly, with Python and Java the client and server processes both use about half of a CPU. The client for node.js uses just about a full CPU and the server uses about 30% of a CPU. The client process also has an enormous number of page faults leading me to believe this is a memory issue. Also, at 10K requests node is only 3 times slower; it definitely slows down more the longer it runs.

Here's the client code (note that the process.exit() line doesn't work, either, which is why I included an internal timer in addition to using the time command):

var zeromq = require("zeromq");

var counter = 0;
var startTime = new Date();

var maxnum = 10000;

var socket = zeromq.createSocket('req');

socket.connect("tcp://127.0.0.1:5502");
console.log("Connected to port 5502.");

function moo()
{
    process.nextTick(function(){
        socket.send('Hello');
        if (counter < maxnum)
        {
            moo();
        }
    });
}

moo();

socket.on('message',
          function(data)
          {
              if (counter % 1000 == 0)
              {
                  console.log(data.toString('utf8'), counter);
              }

              if (counter >= maxnum)
              {
                  var endTime = new Date();
                  console.log("Time: ", startTime, endTime);
                  console.log("ms  : ", endTime - startTime);
                  process.exit(0);