Michael just a quick comment: > On IE, setInterval(0) does not work, so the page skips that test.
What did you see that made it not work? I just tried it and setInterval(0) worked fine, just like setTimeout(0) both provided a 15ms resolution. I did something like this: var dispatches = []; function done(disp,n,start) { if (disp) clearInterval(dispatches[n]); var diff = getTime()-start; var s = "n: "+n+" diff: "+diff+"<br>"; // $('#divLog').append(s); document.getElementById('divLog').innerHTML += s; } function doInterval() // called by button A click { var t = $('#intervalms').val(); for (i=0; i < 10; i++) { dispatches[i] = setInterval("done(1,"+i+","+getTime()+")",t); } } function doTimeout() // called by button B click { var t = $('#timeoutms').val(); for (i=0; i < 10; i++) { setTimeout("done(0,"+i+","+getTime()+")",t); } } -- HLS