I am working on a new website and atm i am testing image placement and size within the site. I actually want to have many more images without slowing down the speed of the main page.
I already removed several plugins which slowed down the site a lot but i still run into several ‘for me’ unexplainable problems.
1: Slow first byte which i can’t get below 0,6 - 0,7
2: An image of only 15k which takes ages to load (2000-4000 ms)
3: A 404 of which i can not find any link or definition for.
It is a wordpress/mysql site on a single dedicated server with enough CPU/RAM/bandwidth which should not be an issue. But since there is totally no load on the server i am afraid that once i get visitors the load times will increase dramatically if i can not decrease the current load time.
Are you using a caching plugin of any kind (W3 Total Cache or supercache)? Odds are that the relatively slow first byte time is coming from a bunch of database queries and a caching plugin can cache the results and just serve a static version of the page if it doesn’t change much. You can also install something like New Relic to show where the times are going on the back-end.
It’s important to do more than a single run to make sure you didn’t just catch a bad example: http://www.webpagetest.org/result/130304_7D_VQC/ (like with the slow image). It could have been a dropped packet somewhere that caused a retransmit (though it seemed really slow). It looked like a one-time issue though.
The “undefined” in the 404 is a dead giveaway that it’s coming from javascript (a variable that wasn’t set is being used). It looks like it is being loaded by jquery but that just means something is using jquery which then loads it. If you load the page in Chrome you can capture a timeline which will give you a full call stack back to the js that attempted to load the resource.
After i posted my previous thread i indeed installed W3 Total Cache and performance increased amazingly .
I tried also to minify javascript with w3 total cache and minify plugin, although performance increased even more, the script stopped working. I tried to make lines which js to exclude but both in W3 and the plugin this didn’t work.
You say the ‘undefined’ is a dead giveaway but for a newbie like me it’s something i am clueless about but atleast i can now focus my search better on how to solve this.
Thanks for your time and if you got an idea on how to minify the js without breaking it then let me know.
The closest I have been able to track it down is that it looks like it is being caused by the slideshow code in slides.min.jquery.js. I don’t know enough about how your site is put together to know if it is a problem with the slideshow module itself or how you are using it.
I wouldn’t worry about minifying. As long as you are gzipping the additional improvement will be negligible.