Hi Purnendu:
In the options panel do you have the page loader selected? If you do the page loader will work as it loads all of your files.
Do you have Mod_Rewrite selected in the super cache settings?
There are a lot of factors when it comes to page load time such as how good the hosting service is, server load, image sizes, page ‘weight’ etc.
Does this answer your question?
Be awesome…
James