iDefrag 1.6.1

Every computer user has noticed it; over time, your system slows down. This is particularly true in these days of constant security updates as replacing operating system components not only increases the potential for file fragmentation, but also creates a more insidious problem—over time, the operating system itself ends up scattered all over your disk.
This, of course, doesn’t show up as fragmentation—after all, the files themselves are probably contiguous—but nevertheless, it takes your machine longer to start up, it takes programs longer to start, and above all, it takes longer to get your work done.
iDefrag defragments and optimizes your disk for improved performance.
Add in the size of some of the files in common use today, especially music, video, graphics and computer games, and even the best filesystem has trouble keeping things contiguous.
Some people say that HFS+ is so good that you don’t need to defragment. In a way, they’re right—HFS+ is pretty good at keeping small to medium sized files from getting fragmented… it isn’t particular good, however, at keeping large files or free space from fragmenting, a particular problem on the Mac because the swapfile must be contiguous on the disk, so you can actually run out of virtual memory long before you run out of disk space if your free space is fragmented.
Another objection—this time raised by Apple—is that existing defragmentation tools may actually slow your machine down by moving files into or out of the “Hot Band”, defeating Panther’s Adaptive Hot File Clustering code. As far as we know, iDefrag is the first defragmentation tool for the Mac that fully supports the Hot Zone, guaranteeing that this is not a problem.
Even if you aren’t interested in defragmenting your hard disk, if you produce products on CD-ROM disks, iDefrag will be of use. Seek times on CD-ROM and DVD-ROM disks are many times slower than those of hard disk mechanisms, so fragmentation really hits performance, in some cases adding many minutes to read times. iDefrag can defragment disk images before they are burnt onto CD or DVD-ROM, optimizing access time and significantly reducing install or read times.
And, unlike other products, iDefrag provides a wealth of information about your files, so you can see which ones are most fragmented and even look where they are on the disk. The screenshots on this page are from a perfectly normal 120GB hard disk, installed in a PowerMac G4 that is used for software development, wordprocessing and other everyday tasks (writing this web page, for instance).
Look how fragmented it has become; most of that is actually down to one or two large files—like /usr/bin/emacs, shown on the right, with 96 fragments—but there are a substantial number of less fragmented files, over 3,000 in fact.
Main features:
- Supports HFS and HFS+ (Mac OS Extended).
- Supports case sensitive and journaled filesystems.
- Supports adaptive hot file clustering (“Hot Zone”).
- Four powerful defragmentation algorithms:
- Compact data, moving all free space to one place.
- Optimize filesystem metadata.
- On-line defragmentation.
- Defragment whilst your disk is mounted.
- Advanced programmable optimization.
- Rearrange your disk the way you want.
- B-Tree metadata file compaction/optimization support.
- High performance user-defined file classification engine.
- Per-block and accurate whole disk display.
- Detailed statistics so you know whether you need to optimize.
- Inspector allows you to view details of individual extents/files.
- Quickly jump to specific files to examine them in more detail.
- Altivec accelerated display for improved performance.
- Auto-update feature ensures you always have the latest version.
- Fine-grained security, just like iPartition.
- AppleScript support.
Version restrictions:
- Demo version will not defrag disks over 100MB in size.