Think of your hard drive as a library and every file on your computer is a book, except your Windows computer doesn’t really care if your “book” fits in any particular location on a shelf. It doesn’t even care if an entire page can fit in one place. So, it “splits” that book, or even pages or words in a sentence of that book, into pieces and places them on the shelves where-ever they fit, then writes down the locations in the “index” or library catalog, then the computer simply remembers where it puts every piece of data from a particular file. In computer terms, this index is called the “File Index” or “Master File Table (MFT)”.
Now imagine you want to read one of your books, but instead of just picking it up off the shelf, you have to run all over your library to gather every little piece before you start to read it. This could get a little exhausting if it’s in a few hundred, or a thousand different locations (which is not uncommon for a computer) and can get pretty time consuming, especially if parts of that book, or parts of pages – even just a single letter, is in the front and back of the library… though for a human this could be a good workout if you want to break a sweat 😅. That is a simple explanation of fragmentation and what your hard drive does every time you open a file.
Defragmenting, or more commonly called Defragging, gathers all of those pieces back into a single location.
While there have been some major advancements in hard drive file structures where fragmentation isn’t as noticeable, it does still cause performance issues to have a heavily fragmented drive. Because of these advancements, defragging seems to have been forgotten in recent years even though it was considered standard maintenance to defragment your computer’s hard drive on a pretty regular basis. Also in recent years, when a person’s computer starts to slow down, instead of trying to figure out how to get back the performance they once had, some just simply go out and buy a new device.
Before we get into how to address fragmentation issues, we need to warn you about some of the differences in storage devices. Here are two major differences to be aware of:
The warning comes from the fact that SSDs have a limited number of read/writes per block and defragmenting performs a lot of read/write operations which can decrease the life of your SSD very quickly, and hence defragging an SSD can be dangerous. With some older SSDs, there is an “Optimization” technique that helps in speeding things up similar to defragging. Also with SSDs, since the data is electronically stored and all pieces are basically instantaneously available, it is not really needed. In the library analogy, it would be like if you had 100 people able to run and go grab pieces of the book all at once, and all of them were seasoned marathon runners. HDDs, in general, don’t have those concerns, though you still don’t really want to defrag too often (for most people once a month is fine – normally after “Update Tuesday” patches have been installed).
With both SSDs and HDDs, you don’t want to abruptly turn-off your computer during these sort of processes as it can really mess up your File Index, meaning your computer doesn’t know where the pieces are at.
There are a lot of options in defragmenting utilities and Windows even has a basic utility built-in. Our longtime personal favorite is Defraggler made by Piriform as it not only shows you how fragmented your drive is but also shows you which files are fragmented and works toward optimization of the file layout of a drive to increase performance. With both Windows Disk Defragmenter and Defraggler, the programs are pretty simple to use and pretty self-explanatory (after opening, click Analyze, and if heavily fragmented, normally 8% or higher, then click Defrag).