View Full Version : Complex Dashboard Example, what is the bottleneck?

21 Dec 2011, 3:46 PM

I'm trying to figure out why the example, "Complex Dashboard" @ http://dev.sencha.com/deploy/ext-4.0.7-gpl/examples/charts/FormDashboard.html is so slow in IE9. In chrome its fine, but IE9, is constantly bogged down, and there is a noticeable delay before the table or graph recognizes that I've moused over them.

Is this just an implementation issue, like bad coding or a faulty design causing so much lag for IE9? Could it have been written differently to perform better?

I also tried the same example in the 4.1 preview and I didn't see any performance gains.

I also have a quick screen capture of IE9 having trouble with this example, http://screencast.com/t/TbfDmbyNW

21 Dec 2011, 4:06 PM
Performance in IE* isn't the best. 4.1.0 beta 1 is about to drop so check the performance with that as the layout system and other stuff has been totally rewritten in many places.

21 Dec 2011, 5:35 PM
Open the developer console in IE9 (F12) and switch to the network tab. See if anything is hanging, and troubleshoot from there.

22 Dec 2011, 8:10 AM
I played with the 4.1 preview a bit more, and did the following to squeeze out some more performance, but I guess i'll still have to wait for the "true beta" for a more accurate reading.

Disabled animations

For all charts

Reduced item counts

For my future purposes the number of items should never go above 6

Disabled highlighting code

IE9's "Profiler" was showing this as a big chunk of time
Went from 72.93 ms to 28.97 ms inclusive time when switching between grid items

With these changes to the example the interface stopped hanging after I selected a grid item.

I also did another test by removing all of the charts, and then the grid was running fast, so I would assume that "charts" are the rendering bottleneck. But I can't remove them, since that's the entire purpose of the example.