When your Mac starts acting unreliably your first line of defense is Apple's Disk Utility, but that solves a small number of problems, such as permissions and disk verification and repair. A good second line of defense is Drive Genius 3 for Mac from Prosoft Engineering. Drive Genius offers repair and maintenance utilities you can use to make sure your hard drive runs at maximum efficiency.
This US$99 suite of programs includes the following modules: Information, Defrag, DriveSlim, Repair, Scan, DrivePulse, Integrity Check, Initialize, Repartition, Duplicate, Shred, Benchtest, and Sector Edit. When you launch Drive Genius you can choose any one of the available utilities from a set of icons displayed across two screens. Each module presents an option to choose a drive, volume or files and folders on the right, depending on the utility's purpose.
Options available for each utility appear in the main window with simple instructions. A question mark icon on the bottom right opens the help file. The simple Preferences offer three options. You can choose to show the custom animation of data moving around a disk as a tool works, check for updates, and turn on email notification when a tool finishes its task. This last preference is a subtle reminder that many of the functions take a significant amount of time to run.
The Information module provides a complete description of your hard drive, probably more information than you want. The balance of the modules are best run after you backup your data, in case of unexpected problems.
Scan, Integrity Check, and Benchtest run read and write tests on your hard drive. They check for bad blocks, the health of your hardware, and in Benchtest, test the drives read and write speeds. As these tests sort of hammer on your drive, any electrical interruption or serious drive problem can result in data loss. That's one good reason to make sure you have a good backup or copy of your drive on hand. The Duplicate module can create a backup for you, but as with many of these tools, it will not copy your current start-up drive unless you start from a different drive. Duplicate creates a bit-by-bit copy of your drive, so you must use a blank drive of equal or greater size to use it. Personally, I prefer Carbon Copy Cloner or SuperDuper! to backup my drives, but including a backup module in Drive Genius just makes sense.
It's actually best to use the Drive Genius startup disk from which to run most of the tools. These tests chew through quite a bit of time, so make sure you run the programs when you don't need the machine for a number of hours.
The problem I often solve using Drive Genius 3 is a slow drive and one that mysteriously is eating up space at a surprising rate. That's where DriveSlim and Defrag come in handy.
DriveSlim is useful to search for large files, duplicate files over 1 MB, Unused Localizations (language files you don't need), Universal Binaries, and Cache and Temporary files you no longer need. I'm not quite sure I understand how it works though. I wasn't happy with the way DriveSlim displays the information, I found that it showed duplicates that were not, but only with files over 320 MB. On one drive, using Mac OS X 10.6.8, it listed both duplicate files and on another, in OS X 10.8, it listed only one file and I had to search for the duplicate in the Finder to see where it was stored. I then manually removed the file stored in the wrong folder. I'm sure that's not the way the tool was designed to work, but I was not confident to just check a box next to the DriveSlim found file and have it decide which file to keep, where to alias that file, or where to back up the file. You can choose which of the files to locate, but if you choose to act on only one type of file, you must run DriveSlim again to work on another type of file. Time consuming to say the least.
Even though most people claim you don't need to defragment a Mac-based hard drive, the OS actually only defragments files that are less than 20 MB. If you create or edit sound, video, or photographic files, you may have some hefty sized files on your drive(s). As Apple states in one of its manpages for XSan: "There are two major types of fragmentation to note: file fragmentation and free space fragmentation." "A file extent is a contiguous allocation unit within a file. When a large enough contiguous space cannot be found to allocate to a file, multiple smaller file extents are created. Each extent represents a different physical spot in a storage pool. Requiring multiple extents to address file data impacts performance in a number of ways."
In short, if pieces of the file you want to use are scattered all over your hard drive, it is working harder to deliver that file to you, slowing your workflow, and potentially reducing the lifespan of your hard drive. In checking a couple of my hard drives I found movie files that were divided into over 2000 fragments and photo files with over 100 fragments. When you run Defrag the files are concatenated into one whole file and the free space is moved to one area. I did test defragmenting my startup drive, not a recommended action to take, but I have a current backup. Drive Genius reboots your Mac into the Command Line and runs the defrag command, which also repairs your drive and reboots your Mac when its done. It worked fine, but a bit unnerving to watch.
The Repair module seems to duplicate the functions of Disk Utility, such as verify and repair disk errors and permissions. It will also rebuild the drive's catalog file.
The rest of the modules are aimed at setting up your drives. You can Initialize a drive and format it for GUID (recommended for Intel Macs) or use the old Apple Partition Map. You can also Repartition a volume, but not your start up drive–unless you start off the Drive Genius 3 disc. Partitioning lets you divide one drive into multiple volumes. I seem to be one of the few people who still partitions my drives and use this function when I first use a new drive. Explanation of initializing, partitioning, and Sector Editing your drive are beyond the scope of this review, but you can find more information on the Drive Genius site and in the Help file. One word of caution, if you do not know exactly what you are doing, never use Sector Edit, because it can corrupt the drive and render files useless.
Last is the newest module, added in Drive Genius 2, DrivePulse. This module loads into your Apple menu bar and monitors your drives in the background. I found it unnecessary on my new iMac, but have used it in the past on older machines. It checks for fragmentation, and file and physical drive problems. On my new iMac most of the drives I loaded yielded a Pending status. It checks drives when the machine is idle, so it doesn't interrupt your work. You can turn it off from the menu item or within Drive Genius.
The one thing Drive Genius will not do is run any tests on a drive that has serious physical problems, which is a shame. I started my tests using a 160 GB Iomega Ego that had trouble mounting. Anyone who deals with drives knows that clicks means ensuing death, but usually you have a little time to remove your files before the drive goes belly up. Well, this drive with three partitions fell off my desktop within 5 minutes. Drive Genius could see it initially, but would not run any tests and I couldn't recover anything from it.
Drive Genius 3 is especially useful if you create or edit very large files. For this review, I tested version 3.2.2, but have also used version 1 and 2 in the past. The price of Drive Genius pales against the cost of a new hard drive. At about $7.60 per module, it helps you keep your machine lean and mean and working at peak efficiency.
OS X 10.6.8 to 10.8.x
1 GB RAM
Does not support Drobo drives
Limited support for FAT32, ExFAT, NTFS, and Software RAID
Upgrade from competing product for $75