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.