On Fri, 1 Jan 2010, David Magda wrote:
It doesn't exist currently because of the behind-the-scenes re-mapping that's
being done by the SSD's firmware.
While arbitrary to some extent, and "actual" LBA would presumably the number
of a particular cell in the SSD.
There seems to be some severe misunderstanding of that a SSD is.
This severe misunderstanding leads one to assume that a SSD has a
"native" blocksize. SSDs (as used in computer drives) are comprised
of many tens of FLASH memory chips which can be layed out and mapped
in whatever fashion the designers choose to do. They could be mapped
sequentially, in parallel, a combination of the two, or perhaps even
change behavior depending on use. Individual FLASH devices usually
have a much smaller page size than 4K. A 4K write would likely be
striped across several/many FLASH devices.
The construction of any given SSD is typically a closely-held trade
secret and the vendor will not reveal how it is designed. You would
have to chip away the epoxy yourself and reverse-engineer in order to
gain some understanding of how a given SSD operates and even then it
would be mostly guesswork.
It would be wrong for anyone here, including someone who has
participated in the design of an SSD, to claim that they know how a
"SSD" will behave unless they have access to the design of that
particular SSD.
Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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