On Fri, 1 Jan 2010, Erik Trimble wrote:
Maybe it's approaching time for vendors to just produce really stupid SSDs:
that is, ones that just do wear-leveling, and expose their true page-size
info (e.g. for MLC, how many blocks of X size have to be written at once) and
that's about it. Let filesystem makers worry about scheduling writes
appropriately, doing redundancy, etc.
From the benchmarks, it is clear that the drive interface is already
often the bottleneck for these new SSDs. That implies that the
current development path is in the wrong direction unless we are
willing to accept legacy-sized devices implementing a complex legacy
protocol. If the devices remain the same physical size with more
storage then we are faced with the same current situation we have with
rotating media, with huge media density and relatively slow I/O
performance. We do need stupider SSDs which fit in a small form
factor, offer considerable bandwidth (e.g. 300MB/second) per device,
and use a specialized communication protocol which is not defined by
legacy disk drives. This allows more I/O to occur in parallel, for
much better I/O rates.
Oooh! Oooh! a whole cluster of USB thumb drives! Yeah! <wink>
That is not far from what we should have (small chassis-oriented
modules), but without the crummy USB.
Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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