PerfectDisk is a defragmentation software by Raxco. (Am using the Professional Edition). For a limited time Raxco is giving a limited featured free edition.
SMARTPlacement is PerfectDisk’s patented default method that defragments all your files, consolidates free space, and optimizes the drive according to file usage. It provides the most complete defragmentation possible and slows down refragmentation of your drive.
Quick Defrag only defragments fragmented files without attempting to place files according to usage patterns or attempting to consolidate free space. It provides the fastest defragmentation pass but is not the most thorough and it should only be used if you have lots of free space.