Here are a few steps you can perform to speed up Firefox. Back to performance basics first, though: the user is the slowest thing attached to the computer. Better use of Firefox's features will speed up the user, so be sure to read the rest of the hacks in this chapter. Fix dial-up modem bottlenecks
Any dial-up modem you use is the slowest network hardware you have, so tune it wisely. Make sure any modem connection is running as close as possible to the maximum speed for POTS (plain old telephone system) phone lines. That line is usually a 64Kbps service (unless you're stuck on an ancient analog exchange). No one gets every drop of 64Kbps out of it, unless they pay a fortune for ISDN, but you should get 53.3Kbps at least.
If you're using Windows, your modem driver and chipset should support the latest compression standards now available. Update the modem and the modem's Windows driver directly from the chipset manufacturer. Look on the modem card to see who made the chips; don't bother with who made the card. If you buy a cutoff switch that lets you isolate your answering machine, fax, and telephone gear while you're on the Internet, you won't strain the line voltage as much, and you'll have less noise causing error-correction delays.
If your connection is still slow, call your telephone provider and complain that their voltages and noise filters are all wrong; they can test and adjust from their end. Call Microsoft and complain that Windows hasn't tuned your PPP connection correctly. Call your ISP and complain that their modem bank isn't negotiating the best possible speed. None of that will do you much good, but it's nice to vent sometimes. Move to broadband
If you're stuck on dial-up, the biggest performance plus you can get from Firefox without using caching is to turn images off. That's in the Options dialog box under Web Features. Turning off images might reduce your Web experience to an unacceptable low, so it's a dramatic step. You can also ensure that Web pages are checked for updates only once per browsing session, instead of every time you look at them. In About:config, find:
browser.cache.check_doc_frequency /* set it to 0, normally 3 */
This preference change shouldn't affect you much if you're just surfing idly. If you spend a lot of time with online message boards or similarly intensive Web-based applications, it might cause confusion, though, so avoid it in that case. One possible compromise is to create a separate "I'm not working" profile and turn the preference on in that profile. Use that profile for recreation only.
Some of the Firefox ad-blocking extensions prevent advertising images from being downloaded, which is a further performance-saving feature.