How does defragmentation benefit the hdd?

[bigpete]

Can someone explain the technical side to how it works, and which the best automatic defragmenter is please!

[richh0323]

Microsoft defrag or disk defragmenter is a software utility designed to help chronologically order the data on the hard disk drive. The theory behind defrag is to place each program together instead of scattered throughout the hard disk drive allowing the read-write head to access the data faster on the hard disk drive. Windows includes an improved version of defrag that is said to place the most commonly accessed data at the beginning of the drive allowing the read-write head a shorter distance to access the data making the computer faster. Generally unless the hard disk drive is seriously fragmented you will not notice a significant difference after defragging the hard disk drive. I would just use the Microsoft defrag command, it's free and you have it if you have Windows.

[kr8r]

Files in your system are stored as a linked list of ‘clusters’ of data on your HD. Although from the point of view of efficient working of the hard discs, it’s ideal to store these files in clusters lying next to each other, file systems can hardly achieve that in a real life scenario. Frequent creation and deletion of files result in having to fragment the files and store them in non contiguous clusters across the HD space.This is called fragmentation. Over continuous adding, removing and editing of files, more files get divided into fragments and get scattered across the HD. The HD being a mechanical device has to move its head each time to a different track instead of reading the clusters in a sequential manner thus causing slow down of applications. For instance when a file is copied or transferred, if it’s fragmented, it would take longer to read the same file as compared to when it’s located contiguously. A magnified form of the above situation, which occurs when numerous files are continuously created and deleted, can be the reason for performance degradation of your computer as it turns out that your hard disc has to do more work to access these non contiguous chunks of data. This problem is all the more significant in today’s age where file sizes are larger, especially with the increased use of Video and graphic applications. In fact while you use your web browser or even Outlook express, temporary files are created in the background and these get fragmented, leading to performance degradation every time you use the applications. To help this situation, the hard disc needs to be defragmented, which is a process of rearranging the data in the clusters in such a way that fragments of the same file are placed in a contiguous fashion. This improves hard disc access speed and hence improving the performance of your computer. Defragmenting your HD could help you ‘speed up’ operations on your computer. This is the process where the scattered file clusters are consolidated into a contiguous arrangement thus making the task of accessing them easier and faster. This happens because the file data is arranged in clusters that lie sequentially rather than in a non-contiguous fashion helping the natural way the hard discs read data. The optimal speed of the HD will in turn help its other performance partners such as the CPU/RAM/MOBO/video card work faster as well. Faster file access time for your HD would mean a speed up of actions such as loading of your Operating System, file transfers particularly for large files, searching of files, file saving and reading in general. It is ideal to run a defragmenter on your HD at least once a week although it would depend on how frequently files are created and deleted on your HD. Sometimes systems may warrant daily defragmentation. It would be a good idea to defragment your Hard disks as part of system maintenance process in your organization to avoid disk related bottlenecks and optimize PC performance. One way of defragmenting is to use Windows Disk Defragmenter. However, there are better third party applications that are available, which have advanced features such as automatic scheduling of defragmentation and are faster too.