Internet Explorer visible repaint

Question

I'm building a javascript map application and I've noticed that in Internet explorer 6, 7 & 8 I can visibly see the lines as the browser repaints the screen from top to bottom when I do things like pan & zoom. Is there anyway I can minimise this? Firefox, chrome & opera are all really fast and I can't visible see the repaint lines.

Answer 1

No, you can't.

The best you can do is to look if you have fixed position or non-opaque elements, that may slow down repaint.

Answer 2

Fqabien Ménager's answer (specifically fixed positions and opacity) is a good start. There's many things that can slow down IE.

The proprietary behavior and expression in CSS (and many times, HTCs) are known to cause slow user interaction performance on all versions of IE. This is because these can be calculated thousands of times per second, usually whenever the user interacts with the page in any way. Those should be avoided.

It's usually best practice for performance reasons to minimize or remove flashy and functionally unnecessary stuff for IE, giving it only what's absolutely necessary to use your site or application. Hopefully IE will come along in performance, but that has clearly not been their focus over the more recent revisions, so it's unrealistic to expect it to keep up with engines like WebKit and Gecko, which have put a high priority on performance, and have improved in leaps and bounds over a relatively short time.