Here are few tricks which can boost the working of Update Panel as they eliminate/minimize the huge data transfer in asynchronous calls.
1. Set the UpdateMode property conditional for each Update-Panel.
Ex.- UpdateMode="Conditional" ;
2. Use multiple Update Panel for each logical section of a webpage so that only a small portion of page which
requires to be independently updated/refreshed can communicate/transfer.
3. Focus on ViewState usage (in terms of data) and minimize it.
4. Set IsPostBack = true, so that page life-cycle on server-side can be optimized.
5. Use PageRequestManager. It manages the Update Panel's asynchronous callbacks.