Hmmmm.....Do Macs have a defrag utility?
I know originally they didn't have one... (mac classic) the system disk came with "disk first aid" which was pretty much like chkdsk/scandisk. I don't think it came with a defrag though.
In an interesting twist- Apple said that the HFS filesystem they used "didn't need defragmenting". Considering that NTFS is pretty much a superset of HFS and conversely, is considered to need regular defragmenting... They can't both be right.
Anyway, not surprisingly, Apple still claims the very same thing nowadays:
http://support.apple.com/kb/HT1375?viewlocale=en_USIt's curious to note that even though they say "you probably wont need to optimize with OSX" they still continue to provide instructions for what to do if you think you do. Which isn't bad but just seems odd. "You don't have to waste your time, but here's how you can if you think you need to" type thing.
Strictly speaking, there is no such thing as a filesystem that can't be defragmented. Eventually, clusters from the same file are going to to be become noncontiguous, and wether the filesystem driver works to avoid such scenarios by essentially defragmenting on the fly or if that work would need to be done later by a third party program is redundant. The question is how does one define when a filesystem/drive "needs" to be defragmented?
out of curiousity (and expecting rather high fragmentation rates) I started disk defragmenter, only to find that the only drive on my system with a non-0% fragmentation rate was my external drive, sitting at a whopping 1% fragmented. Considering I've had this system for a good 6-8 months and used it extensively in that time, that's a tad strange for an OS that "requires constant defragmentation".