Dhtmlxgrid loads slowly when using IE(9,10,11)

Version details : dhtmlxGrid v.3.5 Professional edition build 120731

Here is the code that we have used

Please look at the code above. for 20000 rows this method fails on IE. It takes very long to load data and goes unresponsive. works fine in chrome. can anyone suggest me what to do. i dont want to make drastic changes in the code. “gridbox” is the actual grid control and here gridData is hidden variable which we use to populate the grid.
Your help will be greatly appreciated.

We recommend you to use the smart rendering for the 20000 rows instead of the distributed parsing.
mygrid.enableSmartRendering(true)
Also you may remove the fast operations code as it is not increasing performance for such a scenario.