[Mooff]

Originally Posted by Octavius.

Damn.

--------------- Added [DATE]1312165937[/DATE] at [TIME]1312165937[/TIME] ---------------

By the way I used that link you posted to optimize images and it made my first byte time faster. Thanks a lot man.

What?

Sorry to say that, but how is optimizing images related to first byte time?

Originally Posted by wiki

Time To First Byte or TTFB is a measurement that is often used as an indication of the responsiveness of a webserver or other network resources.

It is the duration from the virtual user making an HTTP request to the first byte of the page being received by the browser. This time is made up of the socket connection time, the time taken to send the HTTP request and the time to taken to get the first byte of the page.

In rough the time adds up like this:
Sending http-request (timing should be similar to a ping) - your webserver (apache?) connecting to your php-system, your php system then will check whether the site can be served via your php cache or whether it has to compute everything new. For vbulletin: running the forum.php including all those database queries, takeing the output, go through the template - build the html page. And finally it goes to the user. At this point your webserver finally does know what images/html it has to send. Up until this point he does nothing and waits. So optimizing images does not influence the first byte at all. I would go for statistical fluctuation here.


You can speed up that process by using a web accelerator (varnish for example). With this it would go like that: http-request goes in, web accelerator sends cached page back. We would avoid all database queries and php compilation etc.
Since we can't really serve our users some cache data which does not check for their permissions, web accelerators can only used (not 100% true) for guests and crawlers.

But well guests and crawlers make up most of the traffic anyway, so varnish is a huge gain, really huge gain in speed and server load.

(web accelerator setup is pretty advanced and probably can't be explained in a simple how to - you need a tech admin who knows exactly what he is doing)