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Mass Data Storage Trends: HDD Technology
By
Roger F. Hoyt, consultant, and Tom Coughlin, Coughlin and Associates
Connectors play an
important role in mass data storage applications, from SCSI and Serial
ATA to USB Firewire, and other interfaces, including internal drive
interconnects.
With the explosion of digitally converged computer, consumer, and
communications applications, hard disk drive (HDD) technology has moved
into many new high-volume applications, such as media players, iPods,
GPS devices, and DVRs. HDD technology is also important in
mission-critical storage applications, such as enterprise storage
systems. In addition, a relatively new technology has arrived—Solid
State Drives (SSD) and cards (SD) using NAND and NOR Flash Memory ICs.
This has created new high-volume connector applications. In the future,
a rapidly growing SSD technology will coexist with HDD, and in some
areas may become dominant.
We thought our readers would be interested in a snapshot of Mass Data
Storage technologies, including hard disk drives. HDD is a major
component of this industry, and has shown remarkable resilience and
explosive growth in a challenging marketplace. A future article will
address SSD trends.
— John MacWilliams, Bishop & Associates Inc.
Mass Data Storage Technology for digital electronic systems continues to
grow in importance and impact. From its origins in high-end computing
and business systems, it has broadened to encompass a wide range of
technologies and applications. HDD technology, in particular, has been a
major demand driver for modern electronic systems.
Mass Data Storage (MDS) technologies include:
-
Solid-state, non-volatile,
flash-memory-based on NAND semiconductor cells
-
Ferroelectric memory
-
Magneto-resistive random
access memory
-
Magnetic recording on
rigid disks and tape
-
Numerous optical storage
technologies
The list of potential
emerging mass data storage technologies continues to increase, including
solid state phase change (ovonic) memory, hybrid flash/disk drives,
spin-torque MRAM, magnetic-spin-based “racetrack” memory, holographic,
and two-photon optical storage.
Magnetic recording-based hard disk drive HDD technology continues to
play the largest and most critical role in mass data storage. With 501
million units shipped in 2007, and expected volumes greater than one
billion units by 2013, HDD technology continues as the most
cost–effective, non-volatile online storage solution.
Price reductions and cost efficiencies may lead to further vertical
integration of all remaining HDD manufacturers, and consolidation of
head, disk, electronic, and mechanical suppliers. Enablers for continued
HDD capacity and performance improvements include current
perpendicular-to-plane giant magneto-resistance (CPP GMR) heads,
discrete track and bit patterned media, advanced signal processing, and
improved security through disk data encryption.
The properties of mass data storage technologies are illustrated in a
“tiered storage hierarchy” pyramid, Figure 1, with the lower capacity,
highest performance, and most costly technologies at the top, down to
the highest capacity, lowest performing, and least costly at the base.
Figure 1, Tiered Storage Hierarchy
(Source:
Horison Information Strategies)
Solid State Storage
SSD must be mentioned because it provides the best performance and
reliability, but its price has historically been too high for broad
implementation. However, technology developments will enable solid state
to overcome this limitation, and become more widely used.
Table 1.
Attributes of Different Memory Technologies
Source:
Objective Analysis, June 2008
Hard
Disk Drive Technology
Of current mass data storage technologies, in terms of shipped volumes
and annual sales, hard disk drives are the largest single component of
the mass data storage industry.
From its initial introduction by IBM in 1956, this technology has grown
to play the most vital role in computing data systems, and over the past
decade, has come to be a vital element in many entertainment and
consumer electronics systems. Along the way, brutal price competition
has caused much industry consolidation. It is remarkable that this
technology, in the face of massive price decreases, has continued to
grow and display Moore’s Law-like technology advances. This is
illustrated by the growth of shipped unit volumes, Figure
2, except this will increase to greater than one billion units by 2013,
driven mainly by growth in mobile, consumer, and desktop products.
Figure 2, Shipped
Disk Drive Volumes vs. Time, By Application
(Source: Coughlin Associates)
As HDD
shipped-volumes have increased, prices per GB have decreased at a rapid
rate, as shown in Figure 3. This has been driven by a number of key
scientific and technical advances in magnetic head, disk, interface,
mechanical, signal processing, and manufacturing efficiencies. While
this has made HDD technology suitable for a wider range of applications,
particularly in consumer and entertainment, it has also created
unrelenting pressure on companies that develop and manufacture HDD
products to maintain profitability and business viability.
Figure 3,
Storage Average Retail Price vs. Time
(Source: Ed Grochowski)
Figure 4, Typical Hard Disk Drive with Key Components Identified
(Picture of Samsung Drive)
For the mass storage
industry, critical advances are required in magnetic and non-magnetic
materials for functional head read-and-write performance at high areal
densities and high frequencies. These advances include: disk media and
overcoats, as well as heads capable of supporting densities in excess of
40 Gb/cm2 (250 Gb/in2); changes in media substrate
technology; and dielectric films less than 1 nm thick for advanced GMR
and TMR heads. In addition, new technologies, such as Discrete Track
Recording (DTR), Bit Patterned Media (BPM), and Head Assisted Magnetic
Recording (HAMR) will require new processes and materials.
Figure 5, Close-up of Actuator Positioning a Head Suspension (HGA) on a
Disk
(Seagate Drive)
Future Critical
Issues for HDDs
Business
Vitality
Ongoing success in the HDD industry will be dependent upon companies’
ability to sustain profitability with continuous global price reduction;
plus, mounting pressure from alternative technologies, such as SSD. This
will require constant improvements in R&D and operational efficiency.
Technology innovation and new manufacturing processes will be required
to maintain leadership against these competing technologies.
Maintaining Areal Density Growth Rate
There are several promising HDD
technologies that should enable higher areal densities. However, these
technologies are expensive to develop and manufacture, and may carry
with them higher manufacturing costs. There are fewer players in the
disk arena and less government funding for advanced technologies at this
time. In a low margin industry such as HDD, the lack of funding could
seriously inhibit commercialization. It is also important to hold down
the cost of the HDD in the face of increasing complexity of media,
laser, and optics applications, and the addition of MEMS, etc.
Competition from SSD
SSD is pressing HDDs in the area of cost
at the low end (portable etc.) where capacities are relatively modest
and entry cost, form factors, and power consumption favor SSD. At the
high end, the superior performance (access time) may threaten the
enterprise (server) HDD business. The enterprise business needs new
designs that make use of the low cost/GB of HDD combined with the
performance of SSD, so that systems look like HDD from a cost standpoint
and SDD from a performance standpoint.
Power Consumption
The
power consumption of HDDs has become an increasing important issue as
energy costs have risen and customers have become more environmentally
conscious. Power consumption can be reduced by making drives more
efficient (better power supplies, more efficient electronics, etc.), but
a large part of the problem is the excessive amount of time a drive
spends in the idle mode, i.e. spinning but not transferring data. These
issues are being addressed.
Table
2, Magnetic Mass Data Storage Technology Roadmap—HDD
Detailed Technology
Roadmaps will be included in the iNEMI 2009 Roadmap.
Implications for the
Connector Market
MDS
technology is the source of many high tech connector applications. In
recent times, rapid growth of both HDD and solid state memory have
resulted in huge connector volumes. We expect this trend to continue
with the following key players:
-
SATA interconnects,
including future SATA developments
-
USB 2.0 and soon, 3.0 at
4.8gb/s
-
New consumer applications
as HDTV programming increases
-
With the advent of SSD,
trends toward smaller, higher density connections
-
Enterprise Storage, SAN,
and NAS, applications at the high end will continue as the
insatiable demand for mass storage continues.
The 2009 iNEMI Mass
Data Storage chapter will be published 1Q09 as part of iNEMI’s
Electronics Industry Roadmap. The MDS chapter includes participation
from a broad spectrum of participants in the mass data storage industry,
government, and academic organizations. It will include the status and
outlook on all key mass storage technologies: solid state, magnetic, and
optical storage. The author is the technical working group chair of this
activity.
 Roger F. Hoyt
is a consultant to the information storage industry in the areas
of advanced technology and manufacturing. Roger has a bachelor
of science degree in engineering physics from the University of
Illinois, Urbana, and masters and doctorate degrees in physics
from the University of California, San Diego. He has held
post-doctoral positions at the University of Cologne and Ohio
State University. Roger has held scientific and management
positions at the IBM Almaden Research Center and Storage Systems
Division, and Hitachi Global Storage Technology. He has served
as a member of the review panel in magnetics of the NIST
Electronic and Electrical Engineering Laboratory and the Mass
Data Storage committee chair of the international Electronic
Manufacturing Initiative (iNEMI). Roger has served in numerous
IEEE activities, is an IEEE Fellow, and is active in Silicon
Valley initiatives involving magnetics.
 Tom Coughlin,
president of Coughlin Associates, is a widely respected storage analyst
and consultant. He has more than 30 years in the data storage industry
with multiple engineering and management positions at companies such as
Ampex, Polaroid, Seagate, Maxtor, Micropolis, Syquest, and 3M.
Tom has over 60
publications and six patents to his credit. Tom is also the author of
Digital
Storage in Consumer Electronics: The Essential Guide. Coughlin
Associates provides market and technology analysis, as well as data
storage technical consulting services.
Tom is actively involved with IDEMA, the IEEE Magnetics Society, and the
IEEE CE Society. Tom is the founder and organizer of the Annual Storage
Visions Conference, a partner to the annual Consumer Electronics Show,
as well as the Creative Storage Conference. Tom is also an organizer for
the Flash Memory Summit and the Data Protection Summit. For more
information, visit
www.tomcoughlin.com. |
