Tweaking firefox

Speeding up Firefox the right way
Speeding
up Firefox seems to be a meme going around the blogsphere lately. Most
of the tips I’ve seen, though, are only for broadband connections with
the latest hardware and only include some of the settings that would
affect performance.

The Firefox Tweak Guide
has the full details on how to speed up Firefox regardless of your
connection or hardware, reprinted in part below. Don’t forget that the
easiest way to tweak user files is with chromEdit extension.
Common to all configurations

These are the settings that seem to be common to all configuration
files regardless of connection speed or computer speed with a couple of
additions - plugin paths can be found with about:plugins and the
bookmark menu delay is turned off.
user_pref("network.http.pipelining", true);
user_pref("network.http.proxy.pipelining", true);
user_pref("network.http.pipelining.maxrequests", 8;
user_pref("content.notify.backoffcount", 5);
user_pref("plugin.expose_full_path", true);
user_pref("ui.submenuDelay", 0);

Fast Computer Fast Connection
user_pref("content.interrupt.parsing", true);
user_pref("content.max.tokenizing.time", 2250000);
user_pref("content.notify.interval", 750000);
user_pref("content.notify.ontimer", true);
user_pref("content.switch.threshold", 750000);
user_pref("nglayout.initialpaint.delay", 0);
user_pref("network.http.max-connections", 48;
user_pref("network.http.max-connections-per-server", 16);
user_pref("network.http.max-persistent-connections-per-proxy", 16);
user_pref("network.http.max-persistent-connections-per-server", 8;
user_pref("browser.cache.memory.capacity", 65536);

A couple settings of note - Firefox is allocated 4096 KB of
memory by default and in this configuration we give it roughly 65MB as
denoted by the last line. This can be changed according to what is
used.

Fast Computer, Slower Connection
This configuration is more suited to people without ultra fast
connections. We are not talking about dial up connections but slower
DSL / Cable connections.
user_pref("content.max.tokenizing.time", 2250000);
user_pref("content.notify.interval", 750000);
user_pref("content.notify.ontimer", true);
user_pref("content.switch.threshold", 750000);
user_pref("network.http.max-connections", 48;
user_pref("network.http.max-connections-per-server", 16);
user_pref("network.http.max-persistent-connections-per-proxy", 16);
user_pref("network.http.max-persistent-connections-per-server", 8;
user_pref("nglayout.initialpaint.delay", 0);
user_pref("browser.cache.memory.capacity", 65536);

Fast Computer, Slow Connection

user_pref("browser.xul.error_pages.enabled", true);
user_pref("content.interrupt.parsing", true);
user_pref("content.max.tokenizing.time", 3000000);
user_pref("content.maxtextrun", 8191);
user_pref("content.notify.interval", 750000);
user_pref("content.notify.ontimer", true);
user_pref("content.switch.threshold", 750000);
user_pref("network.http.max-connections", 32);
user_pref("network.http.max-connections-per-server", 8;
user_pref("network.http.max-persistent-connections-per-proxy", 8;
user_pref("network.http.max-persistent-connections-per-server", 4);
user_pref("nglayout.initialpaint.delay", 0);
user_pref("browser.cache.memory.capacity", 65536);

Slow Computer, Fast Connection

user_pref("content.max.tokenizing.time", 3000000);
user_pref("content.notify.backoffcount", 5);
user_pref("content.notify.interval", 1000000);
user_pref("content.notify.ontimer", true);
user_pref("content.switch.threshold", 1000000);
user_pref("content.maxtextrun", 4095);
user_pref("nglayout.initialpaint.delay", 1000);
user_pref("network.http.max-connections", 48;
user_pref("network.http.max-connections-per-server", 16);
user_pref("network.http.max-persistent-connections-per-proxy", 16);
user_pref("network.http.max-persistent-connections-per-server", 8;
user_pref("dom.disable_window_status_change", true);

One of the changes made for this particular configuration is the
final line where the status bar is disabled for changing web pages to
save processor time.

Slow Computer, Slow Connection
We have entered the doldrums of the dial-up user

user_pref("content.max.tokenizing.time", 2250000);
user_pref("content.notify.interval", 750000);
user_pref("content.notify.ontimer", true);
user_pref("content.switch.threshold", 750000);
user_pref("nglayout.initialpaint.delay", 750);
user_pref("network.http.max-connections", 32);
user_pref("network.http.max-connections-per-server", 8;
user_pref("network.http.max-persistent-connections-per-proxy", 8;
user_pref("network.http.max-persistent-connections-per-server", 4);
user_pref("dom.disable_window_status_change", true);