Disadvantages of prefetch in Firefox

Firefox, by default have a "prefetch" (or preloading) feature which is supposed to speed up the downloading of a site. When you open a web site in Firefox, it automatically start preloading (prefetching) all links contained in the background. So, when you click on a link, it can be load up quickly out of the browser's cache. More details about prefetching at prefeching FAQ

But, even though Firefox is programmed to stop prefetching as soon as a new request is initiated by the user (background download) it consume bandwidth, results in high data quantities that fill up the browser cache quickly and demanding high storage requirements in system RAM. So you need to have a clean caching policy for your web browser otherwise, you just lose all the advantages of Firebox’s speedy downloading of a site. And it is a known fact that, we are rarely visiting all the links in a site. So prefetching feature is generally having no use. So it is advisable to disable this function.

Open Firfox, type ‘about:config’ in address bar and press enter. Scroll down to ‘network.prefetch-next’; double click on it to set the boolean value to false.