How Does Disk Defragmentation Help?

Disk defragmentation can be an effective tool in helping your computer run better.

When a computer starts running slower than normal, many users will think that there is a serious problem. While slow performance can be a result of infection by computer viruses or some other form of malware (like spyware and trojan horses), there are other possibilities. Hardware failure is another possible culprit. However, one of the simplest to fix causes of poor computer performance is one of the simplest to fix: disk fragmentation.

What Is Disk Fragmentation

The first step in understanding disk fragmentation is knowing how a computer stores information on its drives. You might think that your computer simply puts pieces of data in sequence onto the hard drive. When your disc is freshly formatted this the case. As data gets stored and then removed, though, the pattern changes. Once that happens data is stored in the next available space. This can mean putting part of a file in one place and another part in a different section of the drive. A given file can find itself strewn in various places throughout your drive.

The Problem With Disk Fragmentation

Your computer keeps a record of where each piece of a file is stored. So, it knows that the photo you have labeled "mypicture3.jpg" resides in specific sections of the hard drive, even when those areas are non-contiguous. So, it would seem that there is no real problem with having the file fragmented. The issue is efficiency. It takes the computer less time to access sequential points on the drive. So, having a file fragmented makes your computer work harder. That means it runs slower.

What Computers are Affected?

Basically any type of computer can be affected by disk fragmentation. This applies to Macs as well as PC's. Even an MP3 player or other device can become fragmented. The more you save files and delete or create new versions of those files, the more fragmentation you will have. The larger the drive, and the lower the free space on the drive, the worse fragmentation can become.

Detecting Fragmentation

If a computer is running slowly one of the first things you should look at is the possibility of disk fragmentation. Depending on what version of Windows you are running, you will need to run your scan in a different way. The same applies to Macs. In general, though, with Windows machines you should find the fragmentation software located under under disk cleanup when you right click on a drive (in Explorer) or through system tools.

What to Expect

When you check your drive for fragmentation, the computer will give you results that will show the percent of the drive that is fragmented. It will either recommend you defragment the drive or tell you that it's acceptable. If you defragment, plan to live your computer alone for a while. Depending on the size of the drive it can take several hours to do a defragmentation. Essentially the computer takes all the files and moves them around so that they are in sequential positions on your disc. This requires a lot of intermediate moves and is time intensive.

References

• Dell: Disk Defragmentation