IE Page rendering Speed

Question

I am currently struggling to identify where the bottleneck is in an enterprise web app. The app is extremely javascript heavy & only runs on IE, not my design or architecture but my task to improve.

I know IE 6 is notoriously slow for javascript, other than fiddler are there any other IE tools I can use to measure the speed of the page rendering or usual low hanging fruit I can take a look at?

Does anyone know if IE8 is a drastic improvement in javascript processing time? Would anyone recommending IE 8 over IE 6?

Answer 1

I recommend IE8 over IE6 for sure. IE8 also has a javascript profiler so you can get an idea what parts of your javascript code are taking the most time and optimize accordingly.

Introducing the IE8 Developer Tools JScript Profiler

Answer 2

Generally speaking of course, anything more modern (IE8) will run it better than anything old (IE6). I mean even 7 will soon be a product of the past, so 6 is a nightmare.

Answer 3

You can profile javascript with Firebug. There are versions that work in IE.

As for performance, IE8 is much faster. Each tab in IE8 is its own process, similar to Chrome. If you do have IE8, it has a profiler built in, though I still find myself using firebug--mostly out of habit though.

Answer 4

The profiling-tools in IE8 might help find the bottlenecks in IE6 also, but if not, you would have to do some manual debugging yourself.

Simply get the time before and after, and write a message to the document.

An example from http://www.frederikvig.com/2009/05/measuring-javascript-performance/

function somefunction() {
    var start = new Date().getMilliseconds();

    // code here

    var stop = new Date().getMilliseconds();
    var executionTime = stop - start;

    // Print executionTime to the screen/textarea etc
}

Answer 5

A profiler for IE6: http://www.whitefrost.com/documents/html/technical/dhtml/jsprof.html