I mentioned this earlier in the thread
here but I can extrapolate on it some more now.
Internet Explorer 4+ and Netscape 4+ both support receiving the HTML part of a website in GZIP format. This has to be one of the most oft-ignored features of these browsers!
In other words, you can be browsing through a website and each page arrives at your computer in a sort of WinZip format which your web browser transparently unzips and displays.
For broadband users, the delay of the web server GZIPping the page up, sending it, and your browser extracting the GZIP probably negates any possible speed benefit.
BUT!! For modem and/or ISDN users, the speed difference is massive!
The average forum page here is
120-160kb of HTML (this is excluding the pictures!). On a modem, even with compression on, this could easily take 20-30 seconds to download.
However, with MOD_GZIP turned on, the page is already compressed before it is sent.
A 120-160kb page of HTML becomes a 8-14kb GZIP package (that is not a typo!).
Now, the HTML comes in in 2-5 seconds.
So the question is, why was GZIP turned off on the release dates of MA2, GA, and the whole time I was on vacation?
We are on a semi-dedicated webhost, which means we have a "slice" of a dedicated dual 1.2 GHz P4 server with tons of RAM and hard drive.
GZIP is *very* CPU and memory intensive. Actually, my webhost told me that they don't recommend me using it, but the speed benefits were too attractive to pass up. The only time I turn off GZIP is if I expect forum traffic to hit 75-85 users within a 30 minute period. At this point, so many pages are going out and being GZIPped that the CPU and memory are getting bogged down.
Rather than leave it off and expect Michael to check in every hour to see if GZIP is causing problems, I pre-emptively turned it off.
I have asked the vBulletin people to add a feature to throttle, or switch off GZIP automatically when the user count goes over X and then turn it back on afterwards.
I might write this code myself.