Colin said:
You should look at some studies on the effects of fragmentation:
http://www1.execsoft.com/pdf/Diskeeper_Evaluation.pdf
Hmm, do the words "vested interest" mean anything to you? I
notice that they are very careful to leave out any mention
of disk caching, paging, running from memory and all the
other things that are done today to speed up applications.
If an application does a read, process, write, read,
process, write cycle all the time there might be benefits
from defragging. Typical applications don't do that.
Only if an application is heavily I/O bound is there any
benefit from careful placement of files on disks. The only
real-world example I can think of is backup and from my
tests the benefits were only a few percent.
Cheers,
Cliff