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.