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"Fragmentation happens to a hard disk over time as you save, change, or delete files."

I understand with harddisks there is a moving disc that has to spin and seek for files. When the files are fragmented it has to look at several different locations on the disk thus taking much more time compared to if all the files were in one similar location on the disk.

Flash disks don't having moving parts, so the gains from defragmenting should be minimul correct?

So we can agree USB drives can become fragmented... But is there ANY* / realworld performance benefits from defragmenting them?

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migrated from May 23 '11 at 6:25

This question came from our site for system and network administrators.

up vote 2 down vote accepted

Yes, there is a benefit, but oh-so-very-slightly. And it greatly depends on your Flash Disk Controller's fetching strategy.

The drawback, however is immense: Since Flash memory 'wears out' with each writing, you shorten the life of your Flash Disk.

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Drawback immense? People say it's a immense, but is it really? Current flash memory has 100,000+ write cycles, to me it would seem as long as you don't defragment your drive after day you'll be fine. Is there anyway to data on the performance benefits? – payling Apr 20 '11 at 18:14
@payling it is immense because of how defragmenters work: it moves clusters of data around the Flash Disk by reading here and writing there repeatedly and intensively. This heats up the Flash Disk and reduces the write cycle considerably, because if Flash memory gets hot, the stored charges escape much easily. – pepoluan Apr 20 '11 at 23:38
@payling the performance benefit will be negligible. If the FD's controller do a good job of wear-levelling, the rewritten clusters might seem like they're contiguous, but actually stored all over the Flash memory. – pepoluan Apr 20 '11 at 23:41
The drawback is minor. – May 23 '11 at 7:42

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