Defrag Good ?

[Nothinman]

Nothinman - exactly - I would say more than that - most people are probably not even accessing the greater portion of their data , let alone the opsys . So , I am saying that , assuming the disk is close to full , if you access say , 5% of your data regularly , then if that 5% is totally defragmented chances are , you're not accessing much of the disk total area ( not sectors ) . But , if that same 5% will be fragmented , then there's a pretty good chance that you will access most of the disk area .
Same thing Modelworks - I'm not referring to what you describe - but the above - the average user may fill the disk - but only access a small 5 or 10 % - or even more if you like - but it'll still be far from 100 % . This may be , in fact a reason , why disks do fail , as people may be reusing the same areas all the time .

I still don't think the amount of wear on any one area of the disk would be enough to actually wear it out. At least on a mechanical disk, SSDs are a different story. Maybe, if you were constantly rewriting the same area of a disk for years at a time, but I don't think any normal user would have a usage pattern even close to that.

 

[taltamir]

The performance increase is due to the non-fragmented being sequential, which means that the head can read them in single pass and without hopping around the spindle, doesn't it? The less the head have to move, by logic the less will it wear. There is naturally the NCQ too to compensate some swinging.

the heads are very durable. They don't touch the actual drive, they manipulate it via electromagnets. The wear I was mentioning is the wear on the platters by flipping them back and forth with the electromagnet in the head. but yes, you are basically replacing wear on one very durable thing (the plates) with another very durable thing (the head)... Generally speaking both kinds of wear are not very significant.

the funny thing, you are ALSO shifting the wear around... that is, to perform defragmenting you need to read all the data and write it in other locations. The other location is often taken so you have to first move data to free space, then move there. If it is data that is highly defragmented and is accessed often, it will end in reduced wear. If it is rarely accessed you might actually cause more wear by defragging then you would have without.

 

[martensite]

Since I still use mechanical HDDs, I continue to defrag. It's useful to maintain consistently smooth disk performance even on heavily used drives. Just stick an automatic defragger on the system and be done with it...configure once, leave it alone, and don't waste any more time thinking about it.