afmbr - 5:04 pm on Jul 13, 2006 (gmt 0)

(...)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).(...)

Technical view: HTTP requests use TCP which, in turns, usually use IP packets to transfer data. Your browser will be most of time sending full MTU-sized packets on the header request, have them an "Referer" header or not. Of course, omiting the "Referer" header may cause one packet to be omited at the end, but you must be lucky to make it always happen (it suffice a single additional byte to make the TCP stack send another IP packet). FYI, maximum packet sizes usually have 1500 bytes for LAN, and 1400-1492 in DSL connections, so normally it suffices only 1-3 packets for your browser to make the header request. Nevertheless, "wasted" and lost IP packets are "routine" on IP connections (due to congestion, path MTU discovery etc.), so it's not by avoiding one or other packet that your connection will go "faster".

Statistical view: given an average request response size of 10kb (for instance, this very same WW topic listing has currently 11kb), and an average 100 bytes "Referer" header, referral information will acount for only for 1% of the network traffic. (And we even aren't accounting for HTTP headers). If it takes 1 second of network time to service your page request (a fairly slow time), omiting the "Referer" header would give you only 10ms less! NB: you may notice that it takes longer on your browser to load and display a page, but this happens due to other factors, such as HTTP handshaking, browser parser and layout engine, etc, which have nothing to do with the "Referer" header.

So I doubt your browser is anyway faster because you turned off the "Referer" header.