File System Defragmentation
Addressing of sectors of the hard disk drive in use, called LBA, is linear. During the process of removal of files in a file system, the fragments of free areas which are used again by the operating system for data storage at the creation of a new file and an increase of existing ones are created.
The optimization of sequential reading and data search is the primary goal of defragmentation.
Operating systems of "MS Windows XP" family and above use read-ahead technology which is supported by almost all the models of hard drives, analyzing the start of any program and saving the information about the order and frequency of usage of other files by this program in the particular system folder "Prefetch" that allows allocating data even more precisely during defragmentation. For example, if the third file is actively used by the first they are assigned side-by-side.
SMARTHDD defragments, as it makes the operating system after a certain time of inactivity. The given way is the fastest and the closest one about the deterioration of kinematics of an HDD and lifetime of an SSD. Since the operating system will periodically defragment, the use of third-party file system defragmentation programs is useless for the movement of files.