Client side HTML rendering vs UpdatePanel -- which is better

[rupinderbatra]

Hello Everyone,

I am trying to build a website where on click of a button, I am fetching some data from a web service (in code-behind) and displaying it using a repeater control.
The repeater control is wrapped inside an UpdatePanel thus making it a partial page refresh as compared to full page refresh.

Since I am using UpdatePanel control, the HTML is rendered at the server side and sent to the client's browser. It takes somewhere close to 10 seconds to get the data and display the data on the client side. The data contains some image tags also whose loading time is included in the 10 seconds timeframe.

I have read at many places that getting data from a webservice to the client side will be faster than getting the generated HTML from the code-behind function.

While I try to use the clientside javascript to invoke the webservice directly, I do get a faster response(closer to 6 seconds). However, when I render the client side HTML using javascript, the image loading takes a lot of time (another 10-15 seconds).

I am not able to understand the reason for this weird behaviour. If someone can please help me out in this situation, I would be grateful.

Thanks,
Rupinder