Just a quick post showing an iDefrag before and after (iDefrag is an OS X defrag app, basically Disk Keeper Pro for Mac, minus some of the more advanced functionality I guess). Ran an offline defrag, using the “Optimize” algorithm. I wanted to add a Bootcamp partition to my drive, so this shifted all my data to the start of the disk, perfect. Not sure what kind of speed benefit to expect, I don’t expect any, but we’ll see. I’m not sure if Bootcamp needed this space to be free or not, as the drive also has some filesystem errors, but as soon as it completed I was able to setup the Bootcamp partition and I’m on my way 🙂