I'm no expert but I read a lot of forums. From what I understand, disc fragmentation isn't quite the issue as it used to be. Modern drives are much better engineered. Also, supposedly Windows 7 defrags discs automatically. I have numerous different drives/partitions other than my main system disc. I have Windows 7 Ultimate 64 bit. When I run the Windows defrag and analyze my drives all but the main system disc show 0% fragmentation. The system disc usually shows about 2% all the time, which would make sense. I've had this setup for months now and have never ran a manual defrag, and my PC is always shut off when the scheduled defrag is supposed to run. I use this PC for work, so I'm on it 8 hours per day. I render video, remaster audio and create graphic art. Plus I have thousands of email message, documents, pictures, etc. I'm also trying out new software all the time, so there's a lot of installing and uninstalling going on. Still virtually little defragmentation showing up, and my external drives have all mysteriously become defragmented. The background defragmentation process must be working...
[EDIT] To back up my comment about "modern drives" I found the following at Wikipedia. There are other sources out there of course.
"...file systems such as
NTFS (and most
Unix/
Linux filesystems) are designed to decrease the likelihood of fragmentation.
[4][5] Improvements in modern hard drives such as
RAM cache, faster platter rotation speed, command queuing (
SCSI TCQ/
SATA NCQ), and greater data density reduce the negative impact of fragmentation on system performance to some degree, though increases in commonly used data quantities offset those benefits. However, modern systems profit enormously from the huge disk capacities currently available, since partially filled disks fragment much less than full disks.
[6]"