Hello!
We don't really have a document at hand with performance comparisons between Ext.NET 2 and 4 (nor 2 and 3 nor 3 and 4). But better than this, we make it available the whole examples explorer (examples2.ext.net and examples4.ext.net) where you can check your specific component with your browser's development tools.
It is hard to give an overall performance improvement or loss for various reasons:
- additional compatibility adds overhead
- touch support may add overhead for the extra events to listen to
- theme using font glyphs will reduce overhead of page loading as the icons are all pre-loaded from a cached font file (Triton theme-specific improvement)
- more complex and robust controls (with more divs, spans on page, for example) may add overhead
- more controls require other controls to adapt to them. this may add overhead
I personally believe Ext.NET 4 overall performance may be a little slower than 2.x. But it is clear to me that the performance from 3.x to 4.x has increased dramatically. You can check this opening the examples explorers' pages (examples2.ext.net, examples3.ext.net, examples4.ext.net). But all this suggests is that Tree Panels (the heaviest control used on Examples Explorer) has became faster between those versions.
I remember a recent discussion comparing about Ext.NET 2 and Ext.NET 3 examples explorer where I could measure situations where version 3 were much faster than version 2, although overall version 3's examples explorer took much longer to load. I did a quick search in the forums but couldn't find it right now.
Hope all that information helps you a little to understand about performance on Ext.NET between versions!
