On Mar 20, 2006, at 8:26 AM, Thibouille wrote:
Microdrives are only available in CF form factor,
but their capacity/price and speed advantage has been compromised by
recent flash developments, while their disadvantages in terms of
mechanical fragility and power consumption have not changed.
Very true but keep in mind that if long term is what we try to look at
(or heavy usage) that flash tech has another big problem: a limited
read/write cycles life.
In theory, a hard drive has none. Of course hey are mechanical parts
but one know BOTH techs have their problems.
That being said I agree that flash is probably beter in majority of
cases.
Most consumer flash is designed for MTBF of around 100,000 read/write
cycles before a particular bit location fails. Somehow, I think that
filling and emptying a flash card 100,000 times, even if it failed
completely on the 100,000th cycle, allows for a very reasonable use-
value return on its cost. I hardly consider this a "big problem".
For instance, lets say that filling a flash card and emptying it put
every location on the media through 2 read/write cycles, and that no
remapping of bad blocks was possible on a reformat operation
(formatting normally does remap bad blocks...). For a 1G card, this
means 93 exposures in RAW format has incurred 2 full read/write
cycles on a 1G card. That's 50,000 uses of 93 exposures, or 4,650,000
exposures per card before its life is ended. Even if the read/write
cycles were 10x that guess, that's STILL 465,000 exposures in the
life of the card. How many exposures per year do you make?
Hard drives are not rated for longevity by read/write cycles,
although it is surely not infinite either. They're rated for
longevity of the mechanical components, which are far more fragile
than the flash memory's electronic wear limits.
Godfrey
