MatthewHSE - 11:43 pm on Jul 11, 2006 (gmt 0)

Thanks for the comments. I understand about the referer header being useful to webmasters, but included the tip for the sake of completeness. Regarding whether or not it actually helps, all I can say is that I can tell a definite difference when I turn off referers (which is only about half the time, and even then more for privacy than speed). However, I can see how the performance boost may not be as noticeable once you start getting onto a higher quality connection.

I have to say I'm a little surprised at your conclusions regarding nglayout.initialpaint.delay. Actually, if I could recommend a single change to make Firefox faster (or at least seem that way), this one would be it. So 20 milliseconds is the most we'd be able to notice anyway? That's interesting; I didn't know that. Could you explain how one would notice if there are multiple rendering attempts? I've had my nglayout.initialpaint.delay set to 0 for a couple years and have never seen anything that looks like another rendering attempt, but maybe I don't know what to look for. Come to think of it, if multiple renderings are involved, is it possible that a higher-end CPU would make the rendering attempts quicker, and therefore less liable to be noticed? If so, it might be such a thing that people with fairly good processors may prefer a lower value, while those with older CPU's might like a higher value.

If anyone wants to test this, changes to the nglayout.initialpaint.delay setting are applied immediately, without requiring a browser restart. (Actually, I think all about:config settings are like that, but I'm not sure.) You can even have about:config open in one tab, change your settings, then quickly switch to another tab to test the result. This means you can try several settings within a few seconds and see the differences practically side-by-side (and decide if you'd like a larger or smaller value).

Also, I'd like to reiterate that a smaller value gives an illusion of faster browsing by providing instant feedback, even though it may actually slow down the complete length of time required to render the page. As I said, if I could recommend any single setting to increase browsing speed (or the impression thereof) in Firefox, it would be this one. However, since this admittedly has everything to do with your system, and nothing to do with your connection speed, results will undoubtedly vary.