Defragging, or optimizing your file allocation system, on a Mac OS X is probably one joy you don't need to do, and doesn't have the affect as on a PC. Here's why:
* Hard disk capacity is generally much greater now than a few years ago. With more free space available, the file system doesn't need to fill up every "nook and cranny." Mac OS Extended formatting (HFS Plus) avoids reusing space from deleted files as much as possible, to avoid prematurely filling small areas of recently-freed space.
* Mac OS X 10.2 and later includes delayed allocation for Mac OS X Extended-formatted volumes. This allows a number of small allocations to be combined into a single large allocation in one area of the disk.
* Fragmentation was often caused by continually appending data to existing files, especially with resource forks. With faster hard drives and better caching, as well as the new application packaging format, many applications simply rewrite the entire file each time. Mac OS X 10.3 Panther can also automatically defragment such slow-growing files. This process is sometimes known as "Hot-File-Adaptive-Clustering."
* Aggressive read-ahead and write-behind caching means that minor fragmentation has less effect on perceived system performance.
For these reasons, there is little benefit to defragmenting. So that is one less thing in the learning curve for you as a new Mac user....
