GC in IE7 heavily impacted by number of JS objects and string sizes

[nlotz]

Nice article on problems with GC performance in IE7:

Garbage Collection in IE7 heavily impacted by number of JavaScript objects and string sizes

I created a sample to show the performance difference between AJAX calls using XML vs. JSON. In that sample I came across a huge performance problem in IE7 (probably even worse in IE6) caused by too many and too large JavaScript objects. Newer browsers (IE8, FF, Chrome, ...) have better JavaScript engines and better GC approaches. But be aware of too many objects, too large object arrays and too large strings in IE7 as it heavily impacts JavaScript performance.

[watrboy00]

I read this article the other day and it seemed like common sense to me. The more objects you have in memory the greater performance hit you will have. For some reason this totally bombs in IE7. Odd but then again we are talking about IE here.

[Mike Robinson]

As I understand it, the source of many of IE's problems drills down to the fact that it is implemented on what we call today a "dot-net design." In earlier days we called 'em COM-objects, ActiveX controls, or "what do you want to call it today?" This design was built for the Windows user-interface.

IE was built on top of that, and all was well until JavaScript took off and went in its own separate direction, becoming extremely important as it did so. Microsoft responded by creating what they called "JScript" and proclaimed that the differences between the two were "WAD = Working As Designed."

IE has to "map" the allocation-strategy of the JavaScript world "onto" the strategy imposed upon it by its underlying technology framework. And, because millions of computers are out there whose users are using IE exclusively ... IE's bugs will always be there, and they will always be "our concern."