Many users will have come across the disk defragmenter option in Windows and perhaps even used it. Knowing why it is there, how it works and what it does is not only good background for any user’s general knowledge, it will also help you appreciate the working mechanics of your PC and perhaps even lead you to develop more empathy for the sensitivity of your machine’s files and data.
So what is defragmentation?
Defragmentation is not complicated. Fragmentation itself is the term we use to describe how your machine files away data. Very typically, a PC will “write” files to the hard disk in several pieces based upon the room it finds available on the disk in relation to the size and shape of the file you are trying to save.
The problem is that a computer file might consist of 12 pieces, tied quite neatly together. But the first free saving space the “head” finds on the hard disk only fits six pieces of the file, so the remaining six travel onwards across the disk. Two more three piece gaps are found, so the file ends up fully saved but in a total of three locations.
Your hard disk is made up of 512 byte “clusters” but these groups of bytes are not necessarily all aligned next to each other, which is why we use the expression “Random Access Storage”.
Opening and closing up the file on subsequent occasions potentially causes the file to become even more fragmented. Internet and system memory caching will also impact the structure of the hard disk’s files — and periodic clearing of these cache stores (although often a good idea) can lead to further fragmentation.
Defragmentation aims to reduce travel distance for the hard disk’s head by bringing together these disjointed file parts into one consolidated and connected group.
Why is defragmentation a good idea?
If fragmentation of files is allowed to run left unchecked, eventually your PC runs the risk of losing one or more pieces of data altogether. If one of these file elements is a critical system file such as a DLL, then the file as a whole may be at risk of becoming corrupted and unusable.
So disk defragmentation is not just about speed and efficiency, it is also a matter of preserving the longer-term health of your data, which you will naturally want to protect.
How often should you run Windows defragmentation?
While some industry analysts will argue that modern 21st Century operating systems do away with the need for defragging, my advice is that this is not quite so. After all, Windows 7 includes the defragmentation tool and Windows 8 will also continue to feature defragmentation but with an improved user interface and solid-state drive support that visually identifies the storage type of each volume of data on the hard disk.
NOTE: For the more technically minded, it is interesting to note that Windows 8 also includes the option to optimize hard disks using the TRIM command — a call to the operating system to look at the machine’s solid-state drives and determine which blocks of data may be considered no longer in use so that they can be wiped.