What’s slowing down my blog?

Page download time

I changed themes mid December, and according to googlebot’s stats, pages have been taking twice as long to load since then. This got me thinking. What was it I added that caused this? Surely I didn’t make the pages twice as heavy?

  • The new theme was coded from scratch, but the average page isn’t much heavier.
  • I haven’t moved to a new host or server.
  • I’m still using WP-Super-cache, no change there either.
  • The “get recent comments” plugin adds a few database queries, but I didn’t add that until a few days after the jump in the graph above.
  • Although one of my reasons for the redesign was to be able to fit more widgets, I’m currently still using the same ones.

The only other major addition is that this blog now supports gravatars. That means a whole lot of extra images to load, but does Googlebot even load images? For anything but the image search, it wouldn’t have to, right? Another clue is that WP-Super-cache reports page generation times of around half a second. Pretty speedy, and that’s only if the page needs to be generated at all. Most of the time it won’t need to.

For now I’m going to blame it on the gravatars. Load times of around 1000ms aren’t bad, so I’m not considering any changes to the theme, but I guess I need to watch this to see if things get worse.

UPDATE: I came across a great tool today that let me analyse this issue in great depths. Yahoo’s YSlow is an add-on for Firebug that gives you detailed statistics about every element of your page.

UPDATE2: As it turns out, it was hosting related. Apparently the server where this blog is located became slow on the very same day I made my changes. See the very last bit of the graph? It was already starting to return to normal when I took that screenshot.

12 Comments

  1. I am no expert on this but what slows this site in my browser is everything to the right. The middle content part of the page loads very quickly.

    Comment by Joe Gelb — January 22, 2009 @ 12:26 pm

  2. Hi Roy,
    I will add a link to you from a blog I’m writing about successful blogging.

    However I’m also writing another blog which might be of more interest to you:

    Fantasytree – News, Movies, Music, Books, MMORPGs, Games, Reviews and more
    (www.fantasytree.blogspot.com)

    Best wishes
    /M

    Comment by Mindbender — January 23, 2009 @ 3:32 pm

  3. Hi, Roy,

    Does your WP-Cumulus work for WP 2.7? Thanks.

    Comment by Ken — January 26, 2009 @ 5:17 am

    • @Ken: Yes, it does.

      Comment by Roy — January 26, 2009 @ 4:20 pm

  4. Lots of junk to the right – and that horrible flash tag cloud that people laugh at

    Fantastic site though and I click on your ads by Google to give you some link rev. since your info is so strong throughout – I have learned a lot.

    Keep it up!

    Comment by David — January 27, 2009 @ 12:50 am

    • Yeah, it’s highly probable that the sidebars is the heaviest element on the page. But it does contain pretty much the same elements as in the old design. Nothing to warrant a 200% increase in load times.

      Comment by Roy — January 27, 2009 @ 11:09 am

  5. I tend to agree that the tag cloud is an obvious suspect.
    Gravatars, maybe.
    You might check the various php files that make up your widgets – perhaps you’ll find one that’s particularly large or complex.
    Then, I would disable one widget at a time and run the page through a page-load speed checker – there are lots on Google – and run the tests repeatedly since they’re subject to many variables.
    Finally, check your server stats! You may see some obscure file using 10 zillion k of bandwidth. That’s how I found one AJAX form was my number one bandwidth hog, even though it was a minor part of my site.
    That ought to do it, I would think…

    Comment by Agitationist — January 27, 2009 @ 3:35 pm

  6. Hey watch it, WP-Cumulus isn’t slow! :)

    Turns out it was my server after all. I noticed that another site, which has been pretty much unchanged for years had a similar little graph. That one is hosted on the same box.

    Comment by Roy — January 27, 2009 @ 4:36 pm

  7. Nice website and nice Plugin!

    I wanted to tell you that we had the same problem as you…and it could be totally related to the tag cloud plugin you use. We are using textpattern’s technology to create a tag cloud and since we implemented it we had the same performance problems.

    Looking at our database server we saw that it was constantly queried to add, count and remove data related to the user’s access stats. Those stats are the ones that our tag cloud was using at any time.

    So to speak, we deactivated the plugin and everything went smoother.
    Check how much data handles your tag cloud and perhaps you’ll have the answer.

    Hope it helps and best regards.

    Comment by Nacho — February 3, 2009 @ 8:19 pm

    • Hi Nacho. I don’t know if you noticed this, but the tag cloud plugin on this blog was made by me. I know for a fact that it loads the tag data only once, and it causes a little extra load for the client only. Especially when combined with a caching engine the plugins server strain is very low. Thanks for thinking along though.

      Comment by Roy — February 3, 2009 @ 8:26 pm

  8. Your site doesn’t correctly work in safari browser

    Comment by Imporepreency — February 15, 2009 @ 10:17 pm

  9. @Imporepreency: Could you please be more specific? It looks OK through browsrcamp.com and in Chrome, which uses the same renderer (WebKit).

    Comment by Roy — February 15, 2009 @ 10:29 pm