Generally speaking, you do not need to defrag HFS+. I myself had an issue similar to the one described in mozillla's issue tracker.

I know that web browsers (the field I'm interested in) are at least sometimes are affected by fragmentation (ex.: mozilla, chrome). I have sampled too few a volume to generalize my 'results'. Note that I do not intend to make any claims regarding the fragmentation-resistance of HFS+. There's no easy way to tell if your specific problem is caused by fragmentation.īTW answer), the cited Fragmentation in HFS Plus Volumes explicitly says this:.Some people do have issues caused by fragmentation ( 1, 2).There's no built-in or free and popular defragmenter utility for Mac OS X (although there are commercial ones).'If your disks are almost full, and you often modify or create large files') Apple believes these features are enough to spare the majority of their users from caring about fragmentation issues, but also says you ''might'' benefit from defragmenting in some cases (e.g.There are features in Mac OS X designed to prevent some of fragmentation.It's somewhat true: since there's nothing you can do about it without spending $20 on something that might not improve the performance of your computer at all, you could instead focus on other maintenance tasks and just buy a shiny new mac (or reinstall) when the old one gets too slow.īut: An important prerequisite for not caring about disk fragmentation is always keeping some free space on your disk (I couldn't find any recommendation not pulled out of thin air, but 20% is often mentioned). Most people will tell you Macs don't suffer from disk fragmentation, citing technical arguments most people don't understand.

Defragment hard drive mac os x