杨苏立 Yang Su Li, on 11/10/2012 11:25 PM wrote:
SATA's Native Command
Queuing (NCQ) is not equivalent; this allows the drive to reorder
requests (in particular read requests) so they can be serviced more
efficiently, but it does *not* allow the OS to specify a partial,
relative ordering of requests.
And so? If SATA can't do it, does it mean that nobody else can't do it
too? I know a plenty of non-SATA devices, which can do the ordering
requirements you need.
I would be very much interested in what kind of device support this kind of
"topological order", and in what settings they are typically used.
Does modern flash/SSD (esp. which are used on smartphones) support this?
If you could point me to some information about this, that would be very
much appreciated.
I don't think storage in smartphone can support such advanced functionality,
because it tends to be the cheapest, hence the simplest.
But many modern Enterprise SAS drives can do it, because for those customers
performance is the key requirement. Unfortunately, I'm not sure I can name exact
brands and models, because I had my knowledge from NDA'ed docs, so this info can
be also NDA'ed.
Vlad
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