Andrew Gabriel wrote:
Bob Friesenhahn wrote:
On Sat, 18 Apr 2009, Eric D. Mudama wrote:
What is tall about the SATA stack? There's not THAT much overhead in
SATA, and there's no reason you would need to support any legacy
transfer modes or commands you weren't interested in.
If SATA is much more than a memcpy() then it is excessive overhead
for a memory-oriented device. In fact, since the "device" is
actually comprised of quite a few independent memory modules, it
should be possible to schedule I/O for each independent memory module
in parallel. A large storage system will be comprised of tens,
hundreds or even thousands of independent memory modules so it does
not make sense to serialize access via legacy protocols. The larger
the storage device, the more it suffers from a serial protocol.
It's a mistake to think that flash looks similar to RAM. It doesn't in
lots of ways -- actually it looks more similar to a hard disk in many
respects;-)
I was being careful when I said "nonvolatile memory." There are more
choices than flash. Or, if you want to become a zillionaire, invent the
perfect non-volatile memory :-)
-- richard
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