Where Does IE Spend Most Time When Loading a Page?
Jason Weber, Lead Program Manager responsible for Internet Explorer Performance, has released some internal data showing where IE 8 spends most of its time while preparing a page then rendering it, suggesting what websites should be focusing on.
According to Weber, Internet Explorer contains 11 subsystems starting with Networking and ending with Rendering:
- Networking – responsible for communication with the server. It includes services like caching the web content.
- HTML – responsible for parsing the HTML document and creating the DOM. There are similar subsystems for XML, XHTML and SVG documents.
- CSS – parsing CSS style and creating a structural representation of it for later use.
- Collections – responsible for storing and accessing HTML metadata.
- Formatting – Applies styles to each document component.
- Block Building – Each component of the document receives a rectangular block that will be rendered after being layout.
- Layout – Responsible for laying out all the blocks.
- Rendering – Responsible for the final stage of page loading when all the blocks are drawn onto the screen.
There are no results for the latest IE 9 Preview, which is supposed to change the hierarchy among subsystems, but Weber promises that as “we get closer to the IE9 beta we’ll talk more about how these subsystems come together in IE9 to change the performance characteristics compared to today’s generation of non-hardware accelerated browsers including IE8.” Maybe Microsoft will release the tools used to profile the web pages across different subsystems when it unveils IE 9 beta on September 15th.
A typo in the article
I guess this part has a typo
I think you mean IE 8 since you said later in the post
"There are no results for the latest IE 9 Preview"
Re: A typo in the article
thanks for pointing it out but it is not a typo. I said "There are no results for the latest IE 9 Preview", that is for Preview 4. The IE 9 result I published was for a very early preview of IE. Things have changed a lot during this year considering that many performance issues are addressed late while preparing a release and IE 9 uses the GPU now.
don't you have a link to share? I'd like to see details for the 25 ajax sites, for instance.