About 8 years ago when I was actually using early CF cards as "hard
drives" on aircraft carriers** the life of flash drive storage cells was
about 100,000 write cycles. I'm not sure what it is today but I'm sure
it must be at least double that today if not much more. So, yes,
formatting will cause one more write to a write limited device but I
wouldn't worry about one extra write over a life of maybe 2-300,000.
Yes, the internal controller does wear leveling (and even did so back
then) but all it is doing is distributing the wear. It doesn't
guarantee the any given cell actually works. If you do a full format on
the computer it will write to every storage location and do a read back
regardless of leveling. If you fill the disk to the brim leveling is
immaterial. I assume, but do not know, that if the computer says to
mark a cluster as bad that the flash wear leveler will be able to
translate that to the actual storage location that was used and mark
that one as bad.
Me, I'll format the disk once in a great while.
**CF cards survive shock testing much better than hard drives.
This is a 60 pound dynamite charge. The computer and display being
tested are mounted on the barge next to the explosion. The computer
lived but the $10,000 display did not. Had to go back to the drawing
board. <http://www.chucknorcutt.com/barge_test/barge_test.jpg>
Chuck Norcutt
Moose wrote:
>
>> 6) periodically, format the card in the computer being sure *not*
>> to choose "Quick Format". If you do a full format it will write to
>> and verify all storage locations on the card.
>
> I think this is absolutely unnecessary and wastes flash card life.
> Remember, a CF card (and SD(HC)?) has a built in controller with wear
> leveling algorithms. It stores data according to its own rules,
> which aren't linear, and translates actual memory locations to
> virtual mass storage device location data for its interface, so the
> camera/computer has no detail control whatsoever over what's actually
> on the card and where it's stored. All a complete format in the
> computer does is add one more wear cycle to the card. Anybody still
> using a CF HD, sure, go ahead.
--
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