The myth of defragmenting

When files are stored on the hard disk drive they can become fragmented, which literally means that they are broken into small fragments. These can be stored anywhere on the disk surface and when you want to access a fragmented file the disk has to jump all over the place fetching the various parts and this seriously affects the performance of the system. Windows needs to be regularly defragmented to boost the speed. Apple Mac OS X and Linux systems don't need defragmenting. These are common beliefs, but really they are myths. Windows doesn't need defragmenting as often as people think, Apple Mac OS X and Linux systems are not immune from fragmentation, and fragmentation doesn't affect performance that much.

Whether you use Windows, Linux or OS X, it's a fact that files become fragmented on hard disk drives. It is inevitable and it is hard to prevent. All operating systems have features for minimising fragmentation and small files that are frequently accessed are automatically defragmented. This automatic defragmentation only goes so far though, and fragmented files can be found on the disks of all operating systems and it is not just a Windows problem.

It is a myth that Linux and OS X do not have file fragmentation. They do. There are utilities available that both display the amount of fragmentation and help to defragment the disk on Linux and OS X.

It is a myth that Windows systems need defragmenting every day to stop them slowing down. They don't even need defragmenting every week and once a month is fine.

It is a myth that fragmentation seriously affects a PC's performance. It's also a myth that defragmenting a disk significantly speeds up a PC. Modern hard disk drives are extremely fast and this means that fragmentation doesn't affect them as much as it used to when disk drives were slower. Defragmenting an extremely fragmentated disk will definitely speed it up a little, but it has to be really bad before it becomes noticeable. The amount of fragmentation you get over a day or a week just isn't noticeable. Leave a disk for a year and it will be noticeably slower though and then defragmenting it will noticeably speed it up.

Here are 7 disk defragmenters for Apple Mac OS X and 15 disk defragmenters for Windows PCs. Linux is a bit more complicated, but there are disk defragmetation tools out there if you search for them.