So, I’m into day 11 of this month but my hosting bandwidth (which was only recently doubled) is now at 75% used. What’s going on?

Thankfully, Memset provide cPanel and a host of data analysis tools. As you can see from this graph it’s rocketed since mid-October.

I’d love to say it’s because visitors have gone up as much, but that’s not the case. Looking at the biggest bandwidth hogging files, it’s exactly as normal – in fact nothing in particular is causing it.

What did happen mid-October though is that I started looking and changing the site’s caching. I’d been using PHP Speedy with all options switched on (except for GZIP, which I had in my .htaccess file along with a few other tweaks) but was finding that was breaking Debug Bar and jQuery Lightbox For Native Galleries. You can exclude certain scripts from PHP Speedy but that didn’t seem to fix the problem.

I therefore decided to try an alternative method. After some testing I settled on WP Super Cache (to cache the pages – this improved speed but not bandwidth as the same size results are delivered) and WP Minify (this combines and minifies the scripts – something that PHP Speedy did, but I could get WP Minify to work with the aforementioned Debug Bar and Lightbox scripts). I also retained my .htaccess changes.

And that’s how it’s been since. The site’s very quick BUT it looks like the size of the pages being delivered are horrendous.

The cause? Right now, I have no idea and I’m still tinkering – expect to see some site problems over the next few days as I try and resolve it.

What I’ve immediately done is switch off WP Minify and put PHP Speedy back on. Oddly, it’s working with GZIP switched on – if the .htaccess changes are working, this shouldn’t work. I therefore need to check my .htaccess further. Maybe the changes made to this file by WP Super Cache have affected it.

Certainly something has to be done with some urgency and if I have to I’ll abort all changes and had back to PHP Speedy solely (and break those other scripts). My hunch – GZIP isn’t working. Testing tools indicate otherwise.

I’ll update this post, as it may be of use to other developers. And, of course, if you have any ideas please comment and let me know your thoughts.

Update, 16th November.

Sorted. Although online testing tools reported that GZIP was working, it wasn’t. Activating that has put my bandwidth back to normal…

Through some further testing I’ve settled on using WP Minify rather than PHP Speedy. I’m also using WP Super Cache but note that this doesn’t affect bandwidth, only speed.