[Nottingham] HDDs, SSDs, system speedups (Was: Nottingham Digest, Vol 300, Issue 8)

[Camilo Mesias]

Hi,

> Higher read and write speed by using multiple chips in parallel. Also,
> the have the option of resilience if bits fail.

I think they already do that sort of thing but call it 'multi channel'
instead of RAID. Also for resilience they have a small number spare
sectors that are remapped in to cover failures (when manufactured, the
chips usually have some minor defects and being able to soak these up
gives a better yield). I think this extends to failures in the field
as well as those detected at manufacture.

> So... Anything out there for that? And when?

We've been using embedded Compact Flash cards for a while - I suppose
they are the precursors of today's SSDs. The Silicon Systems ones have
some features to make them more rugged (protecting against sudden
power fail*) and report remaining life. Other than those I haven't
seen anything that gives good info on the internal workings of the
cards - they usually ignore the commands for diagnostic info etc.

* although this is great for embedded, it works partly by having
smaller buffers, so isn't good for performance.

-Cam