Firefox has a hidden screen of configuration options that can be opened by entering about:config into the address bar. Note that Firefox will display a menu asking you to confirm this action. Making incorrect changes can cause problems with the browser, so tread carefully!
This can be used to enhance your browsing speed in some versions of Firefox. Look for the following entries:
As you can see, these entries refer to a process known as “pipelining", which by default is disabled. When enabled, it increases the number of requests that Firefox makes to a web page at any time for page content, related images and media, etc.
Normally the browser will make one request to a web page at a time. When you enable pipelining it will make several at once, which really speeds up page loading.
You will need to alter the entries as follows:
Set "network.http.pipelining" to "true"
Set "network.http.proxy.pipelining" to "true"
Set "network.http.pipelining.maxrequests" to, say, 30, allowing the browser to make 30 requests at once.
You can set the first two items to “true" by double-clicking them; the third entry should be double-clicked and the new integer entered.
Finally, right-click in some blank space and select New > Integer from the menu, and give it the name nglayout.initialpaint.delay, with a value of 0. With this entry added and configured the browser should spend much less time waiting for information and more time displaying it on your Mac!
Trying each of the steps listed here in turn should enable you to turn a slow, sluggish browser into one that races to the finish line!