Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Drive Genius 2 and DiskWarrior are both excellent programs that will solve all of your problems.
 
You don't need to defrag on a Mac, but if you really must the cheapest and fastest way to do it is to get SuperDuper or CCC and clone your drive to an external drive. Then reformat your HD and clone back. This is free (as those apps are free), faster, and safer than trusting some derag program to organize every bit on your drive.
 
Don't defrag your mac. I did with idefrag for my large movie files and screwed up my mac pro. Took me months to fix. Let OS X do the defragging.
 
Don't defrag your mac. I did with idefrag for my large movie files and screwed up my mac pro. Took me months to fix. Let OS X do the defragging.

How do you mean it screwed up your Mac Pro? As a bit of a former "windows user", I'm used to the idea (and core concept) of needing to defrag - does OSX really do it on its own in the background?

Thanks
 
Yes, it does. Don't waste your money, don't waste your time.

Like, it's it idle time the system performs a defrag operation? Or is the filesystem is structured in such a way that fragmentation doesn't occur / isn't impactful?

I guess I'm more curious than anything (I never had any intention of buying a defrag package).
 
Like, it's it idle time the system performs a defrag operation? Or is the filesystem is structured in such a way that fragmentation doesn't occur / isn't impactful?

I guess I'm more curious than anything (I never had any intention of buying a defrag package).

OS X auto defrags files under 20mb seeing as thats about 99% of the files on your system, why bother ?
 
Like, it's it idle time the system performs a defrag operation? Or is the filesystem is structured in such a way that fragmentation doesn't occur / isn't impactful?

It's both. Stuff like hot file clustering and defrag-on-read (for files under 20MB) helps to get rid of some fragmentation, but HFS+/OS X deals with fragmentation far better than NTFS/Windows NT does.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.