10k is way to much, even 1k.
So the simple advice is to reduce data and levels.
Redesign your app, add some filters so only currently needed data is loaded etc.
2.1.0 beta 3 (when it comes out soon) will have an infinite List that can handle lots of data. NestedList of course uses child Lists so this should be getting better when beta 3 comes out. There is no setup, List will use it by default.
I changed my Ext.ux.touch.grid component to extend List to get this infinite feature and I tested just yesterday having 5,000 records in the store and it performed quite well actually!
2.1.0 beta 3 (when it comes out soon) will have an infinite List that can handle lots of data. NestedList of course uses child Lists so this should be getting better when beta 3 comes out. There is no setup, List will use it by default.
I changed my Ext.ux.touch.grid component to extend List to get this infinite feature and I tested just yesterday having 5,000 records in the store and it performed quite well actually!
mitchellsimoens, can u fill ur list with 40k records and 14 fields. Then share the result. Also we discovered that our app crashes in data staging for treestore having 6k records and 14 field.