Benchmark

gistfile1.js

function benchmark(times, fun) {
  var accumulatedTime = 0;
  var meanTime = 0;

  (function measureOnce(i) {
    var startTime, endTime;

    if(i <= 0) {
      meanTime = accumulatedTime / times;
    } else {
      startTime = new Date().getTime();
      fun();
      endTime = new Date().getTime();

      accumulatedTime += (endTime - startTime);
      measureOnce(i - 1);
    }
  })(times);

  return meanTime;
}

benchmark(100, function() {
  $.ajax({
    url: 'http://example.com',
    async: false
  })
})