The compressing that is done in Defrag is simply putting the files next to each other. It does this so that the file access time is reduced because the files are closer to the base position of the read/write heads.

It is NOT a file compression in the sense that it removes spaces or repeated characters in a file.

But if you wants your hd to have files spread all over the place its your problem i have defraged hd:s since mid 90:s and never had any problem

 

Yes but what if you move them to another HD when your first HD is full??
Or you want a bigger better faster HD to have your samples on
(It will happen believe me)
Then you have to defrag the new disc and when you enter more samples to it it also needs to be defragged