What is the best and faster way to transfer a DataTable from server side to client side: using JSON format or pure HTML?

This is a one big problem with using AJAX, how to move the data that need to be update from the server side to the client side:

I have tried both ways and I can see that pure HTML is faster, don’t know why yet. It seems like transfering pure HTML and in client side doing innerHTML with JavaScript is working better.

Although, translating the data into JSON format and transfering it to client is maybe a better solution for reading the data and building the HTML on the client side with JavaScript and not in the server.

What do you think? I’m looking for the FASTEST way, a better performance for web 2.0 application.