ST2403

ROUNDTABLE: FLASH
"Another consideration is the trend to extend the life of IT equipment as part of an
environmental sustainability and cost saving strategy. Therefore, customers are now
less willing to rip a perceived old technology out and replace it with a shiny new
one. The impact on data centres will be the running of a mixture of technologies
that could be as old as seven years in some cases, which means the arrival of all
flash data centres is not an immediate prospect." - Roy Illsley, Omdia
time, following a curve that steadily
becomes flatter as technical advances
become increasingly harder to achieve.
Indeed, by around 2010, many observers
were predicting that the technical
development of NAND flash was about to
hit a brick wall in terms of the number of
memory cells that could be packed into a
single flash chip. By then, flash was a wellestablished
and growing feature of the
enterprise IT landscape, thanks not only to
its performance and other advantages
compared to disk, but also because its price
had been tumbling for the previous decade.
If flash chip-makers hit that predicted
technology wall, prices would start falling a
lot more slowly in terms of dollars per unit of
storage capacity.
However, in 2013, Samsung side-stepped
the predicted limitation by shipping the first
so-called 3D flash chips that consisted of
multiple layers of memory cells, rather than
the single layer of cells used previously. This
meant more memory cells per chip, and as
an extremely valuable side-effect, the ability
to store more data bits in each memory cell,
again reducing per-TB prices. All major flash
makers soon followed Samsung's lead, and
since then the number of layers per chip has
grown rapidly. But that was ten years ago. Is
flash now approaching the end or flatter
part of its technology curve?
"People who say: 'Moore's Law is dead' are
ignoring 3D NAND," said Jim Handy,
general director of analyst firm Objective
Research. "This technology has given NAND
flash a new engine to continue to add bits to
the chip, and every year process engineers
find ingenious ways to push it farther than
anyone would have thought possible. That's
a long way of saying 'No' to this question.
Expect to see at least another couple of
orders of magnitude of cost decreases over
the next several years as chip densities
continue to increase."
Announcements at the latest Flash Memory
Summit confirmed that outlook, according
to Leander Yu, president and CEO of Graid
Technology. "Flash memory manufacturers
such as Samsung, SK Hynix, Kioxia, Western
Digital, and Micron will continue to innovate
with roadmaps for greater density with more
layers using stacking techniques,
architecture and design innovations, and
more bits per cell (e.g., penta-level cell or
PLC)," he said. The first multilayer flash chips
that shipped in 2013 comprised 24 layers of
memory cells, and stored 128Gbits. Yu
pointed to SK Hynix' demonstration this year
of a 321-layer chip storing 1Tbit, and
Samsung's prediction made last year that it
will ship 1,000-layer chips by 2030.
Anderson added important context to this
outlook by highlighting the fact that disk
technology is also still developing, and
therefore disk prices will also continue to fall
at around the same rate as for flash. "Flash
technology will continue its inexorable
improvement curve but we don't see that
curve accelerating to gain ground on disk,
(i.e. lowering that 5x-7x multiplier on $/TB)
or decelerating compared to disk," he said.
Amos Ankrah, solutions specialist at
Boston, confirmed the view that flash is still
developing: "There are a few factors, some
outlined in previous answers, which would
indicate that flash is still on the rise in terms
of its technology curve. There is an
argument to be had to considered where
current flash technology transitions into new
technologies, however with the levels of
development which are still being
undertaken by companies that develop flash
storage this would seem to suggest that
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