deferred render question

Hi, I was wondering what kind of data source you need to use with deferred rendering. I have turned on the option expecting that if I display 100 rows at a time the performance should be similar to a table with ~300 rows. This is not playing out though.

Edit: not 300 in this case since only ~6 rows are showing with a 200px window. My understanding is only the displayed rows, and an equal number above and below are rendered by default.

My question would be then, do I need to use the Ajax data source with server side processing ( like the manual's example) or can I just pass it a javascript array like I am doing?

Here is the example code I am using for table creation. Datatables Live is currently giving me a 503 error, and I cannot link to the webpage directly.

            var numCols = 15;
            var numRows = 8000;
            var aoColumns = [];
            var rows = [];

            for (var i= 0; i < numCols; i++)
            {
                    aoColumns[i] = { "sTitle" : "column #"+i }
            }

            for (var i = 0; i < numRows; i++)
            {
            	var new_row = [];
                for (var j = 0; j < numCols; j++)
                {
                        new_row.push(j);
                }
                rows.push(new_row);
            }

            this.$('table').dataTable({
                "aoColumns" : aoColumns,
                "aaData" : rows,
                "bPaginate" : false,
                "bFilter" : true,
                "bSort" : true,
                "sScrollY" : "200px",
                "bDeferRender": true
            });