Dhtmlx Grid Performance Issue for less than 10k Records

Hi , we are using dhtmlxgrid with XML Data source , currently the grid takes more than 40 seconds to load data volume of 7k records, we are using smart rendering and grid.load(url,function) method to load the data , can someone please help what are we doing wrong here , also initially we tried using a json datasource but ran into lot of javascript errors while filtering and sorting for large volume of data (less than 10k) can you please share a demo using json Datasource . please let me know if you require anything else.

Here you can a find a working example with 50000 records:
dhtmlx.com/docs/products/dht … 50000.html

If issue still occurs - please, provide any kind of sample of your code or a complete demo.
Here you can find a tutorial about creating a complete demo:
docs.dhtmlx.com/doku.php?id=othe … leted_demo