I think the real issue is whether defragging is ever truly necessary? To me defragging, if done at all, should be an automatic OS function based on heuristic methods during storing (writing) files to the drive. To task the user with this operation is like saying you must personally change your spark plugs in order to operate your car. In fact, I think that defragging could be eliminated altogether with smarter file allocation techniques. This is especially true on todays HUGE drives where you potentially have lots of "head room" to work with.
A misunderstanding that's not widely reported is that, defragging NEVER fixes any drive errors! In fact, if you suspect you have drive errors you should definitely avoid defragging. Defrag purports to speed up certain types of disk accesses, but there is also risk involved. During a defrag, files are physically relocated on the disk surface, and the FAT (file allocation tables) updated appropriately. If there is any initial discrepancy between the physical file allocation and the FAT to start with, and you defrag, then you've likely turned a small problem into a much bigger one! Also if you have any kind of intermittent power glitch or outage during the defrag process, then your hard drive will be left in an indeterminate state.
I have 3 main systems plus a laptop, and have never defragged any of them. However, I do surface scan in rare cases where a read or write error occurs. In days of old when drives were more limited as to transfer speed, disk space, and buffer size, defragging may have had some validity, but I'm not convinced it is important today, especially given the risks. I know this post is not timely, nor does it even address tezza's question, but as a retired engineer, I have opinions about nearly everything and all the time in the world to share them :D
