[clug] Good overview & projection of HDD densities in next 5 years: Rate of increase is slowing.

steve jenkin sjenkin at canb.auug.org.au
Fri Jan 11 19:18:43 MST 2013

A link in a piece on The Conversation about Archival Data surprised me
(their takeaway was 'a crunch is coming'):

  HDD capacity increase projected down to 19%/year (~4 year doubling).
  Compared with 34%/year for the last 5 years(~2yr doubling)

Nothing was said about SCM [Storage Class Memories] such as 'Flash'.

EMC was also quoted. [Zettabyte = 10^21, cf Terrabyte = 10^12.]


The world’s information is doubling every two years.
In 2011 the world will create a staggering 1.8 zettabytes.
 By 2020 the world will generate 50 times the amount of information and
75 times the number of "information containers" (== files) while IT
staff to manage it will grow less than 1.5 times.
 [2005 0.2ZB]
 [2010 1.0ZB]
 [2015 8ZB forecast]

Here's the article they linked to and some extracts from it.


HDD areal densities measuring data-storage capacities are projected to
climb to a maximum 1,800 Gigabits (Gb) per square inch per platter by
2016, up from 744 Gb per square inch in 2011, as shown in the figure below.
 This means that from 2011 to 2016, the five-year compound annual growth
rate (CAGR) for HDD areal densities will be equivalent to 19 percent.
  For this year, HDD areal densities are estimated to reach 780 Gb per
square inch per platter, and then rise to 900 Gb per square inch next year.

HDD areal density topped the 4-terabyte (TB) mark for the first time in
September 2011 with the introduction of an external hard drive from
Seagate Technology that was designed for desktop applications.
 The Seagate HDD had five platters each with an areal density of 625 Gb
per square inch, equivalent to more than 1 TB per platter.

Only a year earlier in 2010, the highest areal density that could be
achieved for a platter amounted to 550 Gb per square inch. While no
forecast is yet available for the newly minted 4-TB hard disk drive
segment of the storage industry, the current 4-TB products on the market
will surely prove welcome for users hoping to accommodate copious and
ever-increasing amounts of data, including storage-intensive formats
like gaming, music and videos.

Just five years ago, HDD storage capacity per platter was at a maximum
of 180 gigabits per square inch.
 Platters crossed the terabyte level for the first time in 2007, with
hard disk drives comprising two or more platters becoming more common as
HDD storage capacities increased.
 Now with the 1 TB per-platter milestone already reached, 5-TB hard disk
drives using five platters could be available on the market later this year.

Nonetheless, new developments are on the way. For instance, Seagate in
March announced it had achieved in its research lab 1 Tb per square inch
of areal density—30 percent higher than what could be achieved through
PMR technology—by using heat-assisted magnetic recording (HAMR)
technology, a promising approach to enable large increases in the
storage density of hard disk drives.

HAMR technology is likely to lead the way in creating next-generation
HDDs, even though satisfactory costs via HAMR comparable to those of PMR
have yet to be seen.
 In theory, however, advanced technologies like HAMR could extend HDD
areal density to a range spanning 5 to 10 Tb per square inch.


[[They don't mention BPM - Bit Patterned Media or "Shingled Writes" -
wide tracks that are partially overwritten/overlapped. It sacrifices
'update in place'.]]

Steve Jenkin, Info Tech, Systems and Design Specialist.
0412 786 915 (+61 412 786 915)
PO Box 48, Kippax ACT 2615, AUSTRALIA

sjenkin at canb.auug.org.au http://members.tip.net.au/~sjenkin

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