Dongjun Shin wrote:
There are so many flash-based storage and some disposable storages,
as you pointed out, have poor quality. I think it's mainly because these
are not designed for good quality, but for lowering the price.
The reliability seems to be appropriate to the common use. I'm doubious
that computer storage was a big design factor until the last few years.
A good argument for buying large sizes, they are more likely to be
recent design.
These kind of devices are not ready for things like power failure because
their use case is far from that. For example, removing flash card
while taking pictures using digital camera is not a common use case.
(there should be a written notice that this kind of action is against
the warranty)
They do well in such use, if you equate battery death to pulling the
card (it may not be). I have tested that feature and not had a failure
of any but the last item. Clearly not recommended, but sometimes
unplanned needs arise.
- In contrast to the embedded environment where CPU and flash is directly
connected, the I/O path between CPU and flash in PC environment is longer.
The latency for SW handshaking between CPU and flash will also be longer,
which would make the performance optimization harder.
As I mentioned, some techniques like log-structured filesystem could
perform generally better on any kind of flash-based storage with FTL.
Although there are many kinds of FTL, it is commonly true that
it performs well under workload where sequential write is dominant.
I also expect that FTL for PC environment will have better quality spec
than the disposable storage.
The recent technology announcements from Intel are encouraging in that
respect.
--
Bill Davidsen <davidsen@xxxxxxx>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot
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