updated 08:55 pm EST, Tue January 25, 2011
External drive no longer needed to optimize
While Macs generally do not need to be "defragmented" on a routine basis the way PCs do, it can occasionally do some good to optimize the performance of the hard drive by consolidating contiguous blocks of data, particularly if the program or method used understands and respects OS X's adaptive hot-file clustering (aka the "hot zone" of most frequently-used programs). Prosoft's Drive Genius is one such program, and the company has updated its utility to include a new feature called Live Defrag that can optimize the boot drive without needing to be launched from a DVD or secondary drive.
In addition, v3.1 ships on an updated boot DVD for those who prefer to use that, supporting all the latest models and boot technologies. The program also features Drive Pulse monitoring, "slimming" software to remove unneeded languages or PPC binaries from applications, and re-partition utilities and other maintenance tools.
Drive Genius 3 costs $100 and is available directly from the company's website or most Mac dealers, including Apple retail stores. Users of the previous version can upgrade to v3.1 for half price.