What Affects Performance
Whether you run a high traffic WordPress installation or a small, you should optimize WordPress and your server to run as efficiently as possible.
Your theme will have a huge impact on the performance of your site. A fast, lightweight theme will perform much more efficiently than a heavy graphic-laden inefficient one.
The number of plugins and their performance will also have a huge impact on your site’s performance. Deactivating and deleting unnecessary plugins is very important way to improve performance.
The first and easiest way to improve WordPress performance is plugins. Deactivate and delete any unnecessary plugins. Try selectively disabling plugins to measure server performance. Is one of your plugins significantly affecting your site’s performance?
Then you can look at optimizing plugins. Are plugins coded inefficiently? Do they repeat unnecessary database queries? WordPress has its own caching system, so generally speaking, using functions like get_option(), update_option() and so on will be faster than writing SQL.
After plugins come theme optimization.
- Image Files
- Are there any unnecessary images? (e.g. Can you replace some of the images with text?)
- Make sure all image files are optimized. Choose the correct format (JPG/PNG/GIF) for the type of image.
- Total File Number/Size
- Can you reduce the number of files needed to display the average page on your site?
- Combine multiple CSS files into a single, optimized file.
- Query Reduction/Optimization
- Can static values be hardcodedinto your themes? This will mean you have to edit code every time you make changes, but for generally static areas, this can be a good trade off. For example, your site charset, site title, and so on.
- Can you hardcode menus that rarely change? Avoiding functions like wp_list_pages() for example.
Size of Graphics
Making sure the images in your posts are optimized for the web can save time, bandwidth and increase your search engine ranking.
Caching plugins can be easily installed and will cache your WordPress posts and pages as static files. These static files are then served to users, reducing the processing load on the server. This can improve performance several hundred times over for fairly static pages.
Making sure you are using the latest software is also important, as software upgrades often fix bugs and enhance performance. Making sure you’re running the latest version of Linux (or Windows), Apache, MySQL and PHP is very important.
Keeping up with WordPress upgrades is also important.
Paying more for higher service levels at your hosting provider can be very effective. Increasing memory (RAM) or switching to a host with Solid State Drives (SSD) e.g. Digital Ocean can make a big difference. Increased number of processors and processor speed will also help.
Your hardware capability will have a huge impact on your site performance. The number of processors, the processor speed, the amount of available memory and disk space as well as the disk storage medium.