Found this, someone wanna try it out, made by OReilly,
"Speed up page display
To display pages faster, you first need a fast CPU and memory. Don't try the following things on an ancient Pentium II, unless specifically noted here.
Setting the following preference to false is a brutal performance tweak that tells
FireFox to process every byte of Web content as soon as it arrives, rather that buffering it in sensible chunks. This makes
FireFox web-page handling work extremely hard but theoretically puts page content on the screen faster (recommended only for burning-hot CPUs with super-fast display cards and dial-up connections):
content.notify.ontimer /* default = true */
An even more brutal tweak shuts out all interruptions (including user input) while the incoming web page content is analyzed (not recommended at all unless
FireFox is being used as an untended monitoring station):
content.interrupt.parsing /* default = true */
If content.notify.ontimer sensibly remains false, this is the time-out interval for collecting sensible chunks of incoming web page. Lower it for faster incremental page display. Lower it below 10000, and web-page handling will be working extremely hard again (recommended for dial-up):
content.notify.interval /* default = 120000 (micro-seconds) */
For Granny's slow computer, if nothing's arrived recently, then do extra buffering, which saves more CPU cycles. Set to the number of milliseconds to back off each time the network connection is found to be idle (recommended for ancient PCs on dial-up only):
content.notify.backoffcount /* default = -1, meaning never */
Make
FireFox pay more attention to the mouse and keyboard at the expense of other activities. Making this a larger polling delay slows down recognition of user input but marginally improves page display:
content.max.tokenizing.time /* default = 360000 (micro-seconds) */
If the user is in the habit of opening 10 web pages (especially 10 tabs) and then sipping coffee while the pages load, making the following parameter's value larger will speed up page display (recommended for slow CPUs):
content.switch.threshold /* default = 750000 (micro-seconds) */
Make a big memory buffer for big pages. Set to a power of 2 minus 1e.g., 16385 (recommended for broadband):
content.maxtextrun /* default = 8191 */
Here are a couple of additional oddments. The following preference tells
FireFox to start putting received web pages on the screen right away, even if not much content has been received yet:
nglayout.initialpaint.delay /* set to 0, default = 250 (millisecs) */
The following preference tells
FireFox not to bother putting image placeholders on the screen while the real images are fetched, which will also speed page display up a bit (recommended for broadband):
browser.display.show_image_placeholders /* default = true , set to false */
Finally, on Linux/Unix, don't run
FireFox with X-servers and X-clients on different machines; that can be quite slow. VNC (or PC-Anywhere, or Windows Remote Desktop) does not affect
FireFox performance, except for capping the speed at which desktop updates occur. That is not a
FireFox-specific effect, though.
1.11.3. Expand Your Caching
Your best defense against a slow network is a big local cache. In the Options panel, make the cache as big as you can manage. It's really the memory part of the cache that provides the performance, so if your computer is low on memory, a big disk cache won't help much. Buy more memory;
FireFox will find it and use it. If you want to set the size of the memory cache explicitly, use these preferences:
browser.cache.memory.enable /* default is true */
browser.cache.memory.capacity /* -1 = size to fit, 123 = 123 Kb */ "
