You can improve the page speed of your WordPress install, as well as reduce the server overhead, by optimizing your WordPress installation.
The first thing you will need to do is asses whether your website has weak points and what they might be. These two tools can help analyze your website.
- Google PageSpeed Insights: You can submit your URL to this tool to receive a rundown on performance improvements that will benefit your site.
- Pingdom Website Speed Test: This tool also supplies recommendations to improve your website. It will, among other things, tell you exactly what requests had to be made to load the default page of your website.
Remove any unused or redundant plugins. If you're able to complete a task without using a plugin - for example, checking for broken links can be done with a WordPress plugin, or it can be done with a browser plugin.
The larger a page is, the heavier the processor load it puts on the server. If you have a page with big images, it's going to load slower. If you're letting a theme resize an image to fit into a template, you could use image editing software to manually resize the image to match the dimensions it is being displayed in. This will reduce the effort the server has to put out to display a page, since it will no longer have to resize the image in the process.
Try to keep pages under 1-3MB each, for fast pageloads.
Facebook links, Twitter feeds, YouTube videos, and other externally served scripts will affect page load time.This is because rather than having the resources locally, the server must go request those resources from the external host, then load the local page. Keeping these kinds of scripts down to a minimum will help keep your page loads fast.