As a matter of fact, most computer users only use about 20% files in 80% time, that means most of the content on your hard disk keeps in a dormant state in most of the time. By placing the rarely used files/folders onto the slower tracks on your drive (i.e.: near the center of the circle) and moving the frequently used ones to the areas that can be quickly accessed (external rim), we are able to realize the real optimization to disk performance.