SAN JOSE, Calif. — Samsung
Electronics has worked with
server maker Sun
Microsystems to develop a
new 8 Gbit single-level-cell
(SLC) design for computer
servers that it claims
increases the number of
read/write cycles for NAND
flash memory chips
five-fold.
Solid state drives are
just beginning to gain
traction in a variety of
computers from laptops to
servers. A limit of
typically about 100,000
cycles for SLC chips and as
little as 10,000 cycles for
higher capacity multi-level
cell chips has been one of
the big impediments to
adoption to date. The new
chips are expected to
support as many as 500,000
read/write cycles and should
be available later this year
at costs to be determined.
Flash drives are starting
to be deployed to boost
performance and response
times in servers and storage
systems. The drives consume
significantly less power and
space than competing hard
drives factors that also
have driven adoption in
notebooks and desktops.
However, flash drives are
significantly more expensive
than hard disks. Hard drives
for PCs cost as little as 36
cents per Mbyte today. By
contrast flash drives for
PCs cost about $6.65/Mbyte.
The costs for flash drives
are expected to decline
about 43 percent on a
compound basis through 2012,
said Jeff Janukowicz, a
flash drive analyst for
International Data Corp.
(Framingham, Mass.)
Many systems adopting
flash drives including
notebook and desktop PCs and
even Web servers, do not
require high read/write
cycles. However, many of the
high performance server and
storage systems that want
flash drives do need to
support the maximum amount
of read/write cycles.
In June, Sun Microsystems
said it expects to offer
flash drives as options for
virtually all its servers
and storage systems by the
end of the year, said
Michael Cornwell, a lead
technologist for flash
memory at Sun and worked
with Samsung on the new
chips. The server maker has
designed its ZFS file system
to take advantage of the
fast response times of flash
drives which it will use
primarily for caching data.
The new Samsung chips are
unique because they increase
flash read/write cycles
dramatically without changes
at the controller. Typically
to improve endurance vendors
applied to flash-subsystem
controllers advanced error
correction codes and
wear-leveling algorithms
that ensure work is spread
evenly across all NAND
cells.
"We did this all at the
level of the flash chips
themselves," said Cornwell,
although he would not
elaborate on the techniques
used.
A Samsung spokesperson
said the chips will not be
exclusive to Sun but he
could not say when they will
be available, at what price
or how the additional
endurance was added.
Cornwell said better
interfaces at the level of
flash chips and flash drives
will be important for
driving adoption of the
technology in servers. Intel
is leading work on the Open
NAND Flash Interface that
substitutes a typical 40
Mbytes/s flash interface
with a double-data-rate DRAM
interface running at 130 to
400 Mbytes/s.
"That will be a big
driver for use of flash
drives in enterprise
systems," Cornwell said.
A separate effort to
develop a controller
interface for non-volatile
memory could deliver an
improved interface for flash
disks. Today's flash disks
use a wide variety of
interfaces including
traditional drive interfaces
such as serial ATA, SAS and
IDE as well as PCI Express.
IDC projects as many as
2.2 million solid state
drives could ship by 2012 to
create a $900 million
market. That market today is
estimated at about $260
million.
As many as 50 flash drive
makers are edging into the
market, compared to just
seven companies that make
hard drives. "There is a lot
of R&D investment going into
this space right now and a
lot of it is going into
flash controllers," said
Janukowicz.
Indeed, startup Fusion IO
announced in June it is
working with
Hewlett-Packard's storage
group on its proprietary
flash controller technology
that aims to increase
read/write cycles for flash
disks. |