Preload Settings

A cached file is typically generated after a user initially visits a page. This creates a delay for the very first user who views it.

preload-lightbox-new

The preload allows you to create the cache of all the post, page, category, homepage periodically, which helps much in improving future page loads.

Number?

It depends on the power of the server. If you have a ordinary hosting package, you should not set more than 4-6. But if you have a VPS, you can set 10-12.

How it works

The preload feature stars to work after delete cache.

When the Preload feature calls the urls, the cache of urls are created automatically. When all the pages are cached, the preload stops working. When the cache is clear, it starts working again.

cPanel File Manager Cache Folder

Cache Statics

Manually Speed Up Preload

You can get more detail via the following link
http://www.wpfastestcache.com/features/manually-preload-with-cron-jobs/