What Is Fragmentation?

A quick look at a common PC problem and how to fix it
Oct 2010
by Robin Wark

Imagine trying to read a book if its pages were scattered in various locations around your home. It would certainly be frustrating and time consuming. This is just like file fragmentation, a common situation that occurs on your PC. Luckily, it can be corrected through disk defragmentation.

Your computer's hard disk - where your files are saved - is made up of storage compartments or "clusters." Each cluster has a fixed size, for example 512 bytes or characters. If you save a file that is one byte long, it is put into a 512-byte cluster. Or, if you are storing something that is 700 bytes, it is stored in two 512-byte clusters.

In your PC, these clusters are not necessarily physically next to each other. As well, situations occur when you save a file, recall it, work on it and then save it again. When you re-save it, the file might be bigger than the cluster where it was previously stored. The data will have to be split and stored where there is space.

Why does fragmentation hurt your PC?
When Windows saves a file, it makes note of some crucial information. This includes: which clusters make up the file, where these cluster are and in which order they need to be reassembled.

This is a little like having the numbered pages of a book divided into groups and stored throughout your home. In order to read the book, you would need to go to each storage location. Imagine how long it would take to find and read Tolstoy's War and Peace!

When it comes to file fragmentation on your PC, you don't have to scamper from one room to another. However, the head inside your computer, which reads the data, needs to physically move further to track down all of the information for your files. This means reading and writing files takes a lot longer.

What is disk defragmentation?
The way to correct this fragmentation - and to boost your PC's speed - is disk defragmentation. Also known as defragging, this computer maintenance task reorganizes your data so that all the parts of files are stored in contiguous, physical locations. This helps your PC in two ways:

1. It makes it much faster and easier for your computer to find and recall your files.
2. By organizing the files better, your PC's free space will now be a big chunk. This means it is easier for your computer to save files in a contiguous locations and can reduce the opportunities for future fragmentation.

Regular maintenance regime
Defragging should be part of your regular PC maintenance regime. In general, you should consider defragging about once a month. If you use your computer a lot for work and are storing files frequently, you might consider defragging more often. Disk defragmentation is a great way to restore some speed to your PC and to give yourself peace of mind about the health of your PC.

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