Here are some tricks and tweaks that can help you make Firefox run faster or at leas give you a feeling that it runs faster. You’ll have to change some of the settings in about:config section of the settings. To open them, just enter about:config into the address bar and continue.
Decrease page render time delay: nglayout.initialpaint.delay change from default 250 to 0.
Increase the number of simultaneous requests by changing network.http.pipelining and network.http.proxy.pipelining from default false to true and by changing network.http.pipelining.maxrequests from default 4 to 8.
Increase the cache by changing browser.cache.memory.capacity to a higher value, for example 61440.
Move cache to disk when the browser is minimized by changing config.trim_on_minimize to true.
If the settings don’t exist, you have to create them by right clicking on the about:config pane and selecting New -> and then Logical value or Integer to create the setting. After changing the settings try and restart Firefox to test the difference.