Can flash memory become the foundation
for a new tier in the storage hierarchy?
BY aDam LeVenthaL
flash
Storage
memory
THE PAST FEW YEARS have been an exciting time for
flash memory. the cost has fallen dramatically as
fabrication has become more efficient and the market
has grown; the density has improved with the advent
of better processes and additional bits per cell; and
flash has been adopted in a wide array of applications.
The flash ecosystem has expanded and
continues to expand—especially for
thumb drives, cameras, ruggedized
laptops, and phones in the consumer
space. One area where flash has seen
only limited success, however, is in the
primary storage market. As the price
trend for flash became clear in recent
years, the industry anticipated its ubiquity for primary storage, with some so
bold as to predict the impending demise of rotating media (undeterred,
apparently, by the obduracy of magnetic tape). But flash has not lived up
to these high expectations. The brunt
of the effort to bring flash to primary
storage has taken the form of solid-state disks (SSDs), flash memory pack-
aged in hard-drive form factors and designed to supplant conventional drives.
This technique is alluring because it requires no changes to software or other
hardware components, but the cost of
flash per gigabyte, while falling quickly, is still far more than hard drives.
Only a small number of applications
have performance needs that justify
the expense.
Although flash’s prospects are tantalizing, the challenge is to find uses for
it that strike the right balance between
cost and performance. Flash should be
viewed not as a replacement for existing storage, but rather as a means to
enhance it. Conventional storage systems mix dynamic memory (DRAM)
