Sunday, March 17, 2013

Should You Defrag Your Mac or Not?

This is a guest post by Vishal.

Whether we should defrag our Mac hard drive or not – is always a matter of discussion among Mac users. Many say that defragging Mac optimizes its performance while others say that it is just a hypothetical remedy produced by professional utilities. However, Apple too is not very definite about this subject as in one of its article it says, ‘you probably won’t need to optimize your machine at all, if you are using Mac OS X’. After that, it provides the remedies to defragment Mac. Moreover, it also explains some safeguards that prevent its hard drive from getting fragmented and as well says that if you encounter any of the below mentioned scenarios, then defragging your hard drive may get back your machine’s speed:
  • If there are several large files on your hard drive (large files can include video files).
  • Or if the hard drive of your computer is nearly full. That means it has less than 10% free space.
This again creates confusion and pressurizes a user to think that if Macs do not get fragmented, then why Apple has inbuilt safety measures for preventing it from fragmentation. Apart from this, why these safeguards fail to do any needful in above situations? Well, for this we need to know what exactly fragmentation is and what are the safeguards of Mac to prevent fragmentation?

Fragmentation is a phenomenon that occurs with every hard drive irrespective to the Operating System (OS) used and it occurs with time as you keep on saving, deleting, and modifying data on it. Suppose, you store three files on your new machine and after sometime deleted the second one, the hard drive is not smart enough to move the file next to the deleted file to this recently freed space. This causes small clusters of memory space that increase with time as you keep on saving and deleting files. If a new file is saved on these small memory chunks, then it may need to be divided to fit itself in these small chunks of memory. These small chunks of memory as well as a file are called fragments.

Therefore, a fragmented hard drive for sure will lose its speed as it needs to search for all the parts of a fragmented file, when you try to access it. As well as when you save a new file on this fragmented drive, then too it will take more time as it needs to search for a contagious location and if not then it must be divided into parts to be saved. 

Now let us talk about the safeguards of Mac OS X that prevent it from being fragmented. The HFS+ file system of your Mac OS X generally does not utilize these small memory chunks for saving a new file instead; it searches for a sufficiently large space and saves your file there. Moreover, the ‘Hot File Adaptive Clustering’ makes a region of all the frequently accessed files by defragging them and thus, speeds up their access. Moreover, the OS X in routine checks for all the small memory chunks and converts them into one large space and again prevents the free space fragmentation.

However, these automatic defragmentations fail when your file is very large (i.e. larger than 20MB) or if your file is fragmented into 8 or more segments. Moreover, if hard drive is almost full (that is it is filled up to 90%), then the OS X has to utilize the small memory chunks for saving a file for which it has to divide this file into small portions. Therefore, it, for sure will lose its speed and deteriorate its performance.

About the Author
Vishal is an expert Mac OS user & author who is sharing some inside information on Mac drive defragmentation