ttfb very high . 5 seconds on average!

Web Performance Discuss Test Results
1

http://www.webpagetest.org/result/120612_7F_4G5/

Bluehost shared, using cloudfare and w3tc

any ideas?

2

For starters, test the page with www in front so you don’t have to pay the penalty twice (including the redirect). If your redirect is currently being done by wordpress I recommend making it part of your .htaccess so Apache can do the redirect without having to run all of the wordpress code (should reduce the redirect time to a few hundred ms at most).

To figure out what is causing the slow TTFB for the actual page you can turn on debugging in W3TC and look at the page source. At the end of the HTML there will be comments that tell you how long the database queries took, if the page was able to be served from cache, etc.

3

So , here it is:

4

Try logging out or using a browser in incogneto mode and grabbing the debug information again. W3TC bypasses the caching for logged-in users so the debug information isn’t useful in this case:

Caching: disabled
Reject reason: User is logged in
Status: not cached

Interestingly, W3TC sees that it took 1.3 seconds to generate the page but only 31ms was spent on database queries and 83ms on object access. That means there’s something else really expensive going on (which is pretty unusual).

Can you try disabling all of the plugins you have installed and see how that changes things? If it improves substantially then it’s a matter of turning them on one at a time to see where the pain is. If not then it’s either in the template code itself or in the server configuration for PHP (less likely).

It kind of looks like there may be a plugin that is making calls to an external service and that is adding to the time (possibly for Spam checking or something like that).

6

SO I deactivated a bunch of plugins…logged out…logged in…tried 20 ways…and nothing.

Now though, randomly, the numbers are much better. With an overall load time of 3.7/1.6 1st/2nd, and ttfb of .32/.33

If I test again during the day and have a similar result - perhaps it is just my host (bluehost)?

Also, if I have a setting on w3tc wrong, could it be re-building the cache too often, affecting load times? which setting should I look at to be surE??

7

It’s probably not a frequency of rebuild problem. It’s very likely a function of being on slow shared hosting and variable performance for some aspects of the server (either filesystem or database access). From the looks of things in the debug logs, the database looked to be doing just fine.

It’s unfortunate but a lot of the shared hosting providers are very oversubscribed and these are actually faster than a lot that I have seen (I have seen TTFB’s of > 20 seconds on some of them).