I second what others have posted about performance already - Ext 3 performs better across the board and I'm glad Sencha is now looking into it.
@MrSparks - Thank you very much for the detailed analysis.
Also experience performance issues in IE 7/8/9 compared to Firefox and Chrome.
I am using a Viewport where the Center region is outputting HTML. When I show 6k rows in a table format, Firefox and Chrome handle it fine... but IE slows to a halt.
But it only slows to a halt when the table is displayed INSIDE of the center region. If I just display the HTML with no ExtJS 4 wrapper, it works fine. So there's something within Ext 4 that is crippling rendering time in IE browsers.
@NoahK17 are you saying that the 6k rows in a table is html and does not create ExtJS components? What happens when you show only a very small html in your center region in IE?
The 6k row "table" is raw HTML, generated via PHP then patched into the center region of the border layout. I'm probably going to re-construct the table to use a Grid Ext component instead to see if that helps.
As to your second question: Smaller tables (hundreds of TD's and TR's) render just fine in all three browsers I've tested (Chrome 6, Firefox 4, IE 9)... it's just IE that stumbles when you get to ~1k rows. Firefox and Chrome handle the content just fine.
Problem is that Ext 3 was already much slower than Ext 2.3. We tried upgrading from Ext 2.3 to Ext 3 over a year ago and got a good kicking from our customers about how slow it was.
Just seems wrong that 2 major releases have seen a decrease in performance.
We had the same problem with our products... our customers gave us so much bad feedback when we upgraded our main product that we had to revert all but a few of them. We also failed in convincing support about the slowness, they didn't want to hear it or address it... it was especially noticeable with IE7, which is the most used browser by our customers (schools/corporate)
We were hoping v4 would fix these issues since performance was so hyped up at the conference... now we're looking at running on an unsupported version (v2) going forward or having to rewrite our products in a different framework which isn't likely
Could this performance issue is partly from ExtJS 4.0 dynamical class loading as the schema sample page is a sample only? Cant believe that Sencha said it rewrite the layout engine to be faster and the fact is it is slower?