Windows NT users have discussed (online and off) the effects of fragmentation on NTFS, so I won't rehash them all here. I'll just say that NT slows down noticeably when you defragment the hard disk.
Although a handful of NTFS defragmentation programs are available, Executive Software's Diskeeper offers the richest feature set. Unfortunately, because Diskeeper was the first defragmentation program for NT, it came with its share of problems. Users who tried to beat up on the program usually ended up with the program beating up on them.
Diskeeper 2.0 fixes most of the anomalies in the older releases, notably, the upgrade-itis flaw in Diskeeper 1.X's design. (Larry Kahn's "Diskeeper for Windows NT," April 1996, reviews Diskeeper 1.01 for NT 3.51.) Remember when Diskeeper required a patch every time Microsoft updated NT? Well, the NT 4.0 kernel now contains the defragmentation hooks, so Diskeeper can run--unmodified--on NT 4.0, NT 4.0 with Service Pack 1 (SP1), NT 4.0 with SP2, and all future updates of the OS. This improvement is good for Executive Software, because the company won't have to play catch-up to Microsoft anymore, and it's good for us users because we won't have to hunt down patches every time Microsoft comes out with a new version of NT. (For the down side, see CTRL+ALT+DEL, page 200.)
Diskeeper installs as a service, which is how it does most of its magic. Because Diskeeper is a service, you can set it to defragment your hard disks, even if you're not logged on. Diskeeper is also the only defragmentation tool for NT that works without user intervention: The program includes an internal scheduler, shown in Screen 1, that you can use to schedule Diskeeper to run against your disks at regular intervals. The scheduler's level of detail is a nice touch--you can set the days when the program runs. You can even set Diskeeper to run continuously against stubbornly fragmented disks.
When you first run Diskeeper, you'll probably want to run its analysis program to see how fragmented your disks are. Diskeeper uses color-coding to display fragmented files, system files, contiguous space, free space, and the page file's location on the disk. Analysis of my 1GB disk identified 97 fragmented files with 350MB of free space. Diskeeper, running at normal priority, took about seven minutes to whittle that number down to four fragmented files. This quick performance seems to support Executive Software's contention that Diskeeper 2.0 is faster than Diskeeper 1.X. I didn't see a tenfold performance increase, but I don't think anyone has, outside the vendor's labs. Another benefit to Diskeeper's design is that it runs online; that is, you don't have to schedule downtime to defragment your hard disks.
You can overlook most of Diskeeper's problems because they are inherent in the NTFS code. For example, Diskeeper requires a significant amount of free space. On an average hard disk, Diskeeper requires roughly 20 percent free space for optimal defragmentation, but that figure varies. How many of us have that much free space on our hard disk? The main factor that influences Diskeeper's performance is file size: The larger the files on your system, the more free space Diskeeper requires to work at an optimum level. Diskeeper can't defragment the NT swap file because NT locks it for exclusive use. You can eradicate page file fragmentation by moving the swap file to another drive and deleting the original copy. NT re-creates the page file on startup, but only if it's not there to begin with. Thus, the page file becomes fragmented if you don't delete it between boots--which is nigh impossible to do on NTFS partitions.
All in all, Diskeeper 2.0 represents an excellent value. If you own Diskeeper 1.X, you can download the upgrade to 2.0 for free from Executive Software's Web site. Because Diskeeper also supports FAT disks (i.e., 16-bit FAT disks--Windows 95's FAT32 file system is unsupported and unreadable on NT), you can use the program to automatically defragment all the disks on your system every night. It's safe, it's automatic, and it's a useful addition to any NT system.
Price: $75 for Workstation; $399 for Server