gistfile1.txt

var n = 100000;

console.time('innerHTML');
var e = document.createElement('div');
e.innerHTML = Array(n+1).join('<span></span>');
console.log(document.body.appendChild(e).children.length + ' inserted!');
console.timeEnd('innerHTML');

console.time('DOM');
var d = document.createElement('div');
for (var i = 0; i < n; ++i)
  d.appendChild(document.createElement('span'));
console.log(document.body.appendChild(d).children.length + ' inserted!');
console.timeEnd('DOM');

100000 inserted!
innerHTML: 156ms
100000 inserted!
DOM: 354ms