How can I improve the performance of my IE6 / 7 JS sites?

Question

So, I recently participated in the rewriting of the site, and we went live in order to improve the previous one in all respects (no, this is not ideal, we live on time and always improve: D) with one exception: in IE6 / 7 it will be blocked after showing the page. I know that JS, as with him, quickly disconnected, and I know some things, such as the simplegallery plugin, which we use very slowly, but even with this, and Google ads removed it while crawling (+ 8 sec). I looked at the Firebug profiler and made many JS / CSS changes, such as:

• Moving all JS except our img error handling at the bottom of the page
• Improving all jQuery selectors for maximum performance
• Transition to jQuery 1.4
• our main user JS (main.js) works through JS Lint
• Sprint commonly used images
• Reducing CSS selector complexity

This was good for all browsers, and I know I can do even more, but I don't see the significant improvement in IE6 / 7 that I need. We use DD_roundies_0.0.2a.js for IE7, but not for IE6. I tried DynaTrace, but could not see anything obvious, although I lost a little its depth.

Example List Page

Search page example

Can someone see what I might miss here and / or point out some good IE profiling tools?

: , YSlow, PageSpeed ​​ Chrome Developer Tool. , . , , . IE6/7, , JS.

2: Chrome Frame IE6 . , , , IE6. , JS , , .

Answer 1

"common.js" script IE6. ​​ .

.

function ts() { return (new Date).getTime(); }
var t0 = ts();
// some of your code
var t1 = ts();
// rest of your code
var t2 = t();
alert(t1-t0); // milliseconds between t0 and t1
alert(t2-t0); // ms between t0 and t2

, script .
, , IE6.

Answer 2

jquery http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.js, , -.

, YSlow Firebug, , , .

Answer 3

Google Chrome Frame, IE - javascript engine

http://code.google.com/chrome/chromeframe/

Answer 4

"omniture.js".

, omniture.js IE6.

SpeedTracer Chrome . , js V8.

Answer 5

javascript , DOM, , , , . .

Answer 6

LABjs RequireJS: JavaScript Fun Way, , .

Until the last generation of browsers, the tag had some really disadvantageous performance characteristics to it. Namely, the "block" tags, that is, they stop everything else that is loading / executing on the page, while they are loading and while they are being executed. Not only did they stop all the rest of the page, they even used to stop loading any other tags.