Internet explorer compatibility view performance

Question

I use IE9 and I know that the compatibility mode uses IE7 render engine but what about performances ? If the compatibility mode is enabled, does it slow the page load and the javascript ?

I don't see major differences when switching from one to another.

Answer 1

Internet Explorer 9 includes performance improvements across the HTML parser, CSS engine, mark-up tree manipulation as well as the JScript runtime and the associated garbage collector. Memory leaks due to inconsistent handling of circular references between JScript objects and DOM objects were corrected. For better security and stability, IE9 uses the Loosely Coupled Internet Explorer (LCIE) architecture and runs the browser frame and tabs in separate processes. LCIE prevents glitches and hangs from bringing down the entire browser and leads to higher performance and scalability. Permissions for ActiveX controls have been made more flexible – instead of enabling or disabling them globally, they can now be allowed on a per-site basis. So all of those features will be unavailable in Compatibility mode.