ExtJS: Performance Best Practices
With the Sencha dev team hard at work improving the underlying performance of ExtJS 4 there has been a lot of talk on the forums about how to write fast applications. Those of us who've been using ExtJS for a while will all have experienced sluggish UIs and in many cases the problem lay in our applications, not the library itself.
I thought it might be interesting to get some discussion going about what techniques people have used to improve UI performance in their own applications. It would be interesting to compare notes and possibly generate some metrics to see which 'optimizations' actually work. If there's sufficient interest perhaps it could even turn into a blog post.
Different Settings For Different Browsers
Whilst you may be required to support older versions of IE, it isn't necessarily the case that you need to provide an identical UI to the one you offer in newer, faster browsers.
Are there things you could cut in older browsers to help performance? Animations and visual effects are an obvious example but there are others. What about the page size of your grids? It might help to reduce it in older browsers. Many UIs have redundancy built in to make them more convenient, e.g. 3 different ways to do the same thing. Is that strictly necessary?