If you didn't know already, UltraLinx runs on Wordpress because it's by far one of the best CMS platforms out there. Big names like TechCrunch also use Wordpress because it's super simple, and with it being open source there is so much you can do with it.
However Wordpress is also quite complex and has a lot more going on behind it, than just html and css placed on a server. People who own Wordpress sites will know this.
There's a lot more processes going on to show you a web page, compared to a website without a CMS system. So speeding up your CMS system where you can, and utilising the server resources you have, is vital to having your site load as fast as possible. This infographic will be able to help you in keeping your Wordpress loading as quickly and smoothly as possible, with the use of some neat tricks and plugins.