1) which RF version used? Check with latest 3.3.3 if using older one.
2) Reduce number of row's which loaded to the client by specifying rows attribute.
3) Define NONE or NEKO filter in web.xml (see reference guide) in order to improve ajax performance in general.
how can I add ajax capability to scrollableDatatable ?
It's loads data via ajax out-of-the-box.
I am going to upgrade my richfaces.
you said "It's loads data via ajax out-of-the-box."
I am not clear on this. Could you explain it in a little more detailed ?