20s+ for a Joomla site

Hello,

Please help me explain (like I’m 5) what went wrong and how do I optimize this.

[url]http://www.webpagetest.org/result/130130_DM_8AN/1/details/cached/[/url]

Thank you

There are a bunch of things that are part of your site that do not change (specific images, javascript, style, etc). Your server can tell the browser “this file isn’t going to change for X seconds/days/years, feel free to store it and don’t ask me for it again” by including an “Expires” or “Cache-Control” header in the response.

Without the header, the browser doesn’t know if the copy of the file it has is the latest so it has to ask your server “hey, give me this file if it changed since I got it”. Since the files didn’t change, the server responded with a simple “not modified” message and the browser went ahead and used the copy it had.

With the header, the browser would not have to check every one of those files with the server every time the page is loaded.

As you can see, even though the browser didn’t have to actually download the content, just checking for all of them can take quite a long while.

That said, the 5 seconds for the server to respond for the base page itself (the first request) is a big contributor to the 20 second load time and that is going to be a server-side configuration issue (overloaded server, poorly tuned database, some other stuff that someone who knows what they are doing should look at).

Thanks for the explanation.

Would installing Joomla cache extension such as these help improve a bit?

Yes, a cache extension (or joomla’s built-in page caching) can help hide the issue.