Fortunately, computer storage technology is evolving with hard disk drives (HDDs) at its core. Multiple streams of future innovations are being explored by scientists and engineers to evaluate possibilities as the path is paved for tomorrow's standards - and volumes. Looking at some potential scenarios, global storage leader Western Digital gives some thought to the future of hard drive technology.
Digital content generated in 2010 alone was more than all the data created in the previous 5000 years[1]. Given the 1.8 trillion gigabytes in 500 quadrillion "files" on track for this year, the digital universe represents nearly as many bits of information as there are stars in our physical universe.[2]
Industry analysts estimate that 75% of universal digital content is a copy[2], which is contained in an IDC report titled Extracting Value from Chaos, on the exponential growth of the digital universe. Some statistics cited include:
In terms of sheer volume, 1.8 ZB of data is equivalent to:
Driving demand
With the world's electronic data expanding so rapidly, moving to surpass 2.0
ZB, driving factors include:
Anything stored on a smartphone or tablet is duplicated, backed-up and/or stored somewhere else and as more companies engage cloud services, the need for storing and securing data will only increase. Organizations storing important data in cloud platforms have considerable redundancy, backing up information in multiple data centres. Online communities and services such as Facebook, Flickr, Google+ and Twitter are backed up as much as three times. Interestingly, much of the data stored in the digital universe is not user-generated - it is shadowing technology - data created around user transactions and preference queries ("Maybe you would also like...?") following online purchases and continuously updated streams of analysis stored, directed and accessed in the vortex.
While software and component supplier companies strive to develop their own solutions to cope with the digital explosion, competitive storage hardware manufacturers (Western Digital (WD), Hitachi Global Storage Technologies (Hitachi GST), Marvell, Seagate Technology, Xyratex, LSI, Texas Instruments, Fuji Electric, Veeco, Intevac, KLA-Tencor, and Heraeus) have joined forces to address these huge challenges.
The International Disk Drive Equipment and Materials Association (IDEMA) formed a special forum, Advanced Storage Technology Consortium (ASTC) to mindshare technical evolutions for next-generation hard drives. With demand for greater capacity and faster speeds always constrained by price, the processes for researching and developing future storage technologies could wind up too costly, risky, or unmanageable for any single drive manufacturer. Under ASTC, cooperative endeavours are in motion to establish common specifications collectively for future platforms.
As capacity and density requirements spiral upwards, storage companies face barriers with current technical standards. Building the bridge to future technologies presents challenges for both traditional drives and solid state drives (SSDs). For SSDs, as NAND flash reaches semiconductor limits for lithographies below 1X nanometres, new technologies such as Vertical NAND or 3D Stackable NAND are striving to extend NAND flash technology. Other technologies contending to succeed NAND include: 3D Resistive RAM (RRAM), Phase Change Memory (PCM) and Spin-Transfer Torque Magnetoresistive RAM (STT-MRAM).
Hard drives presently hover at maximum capacities of 3TB in the 3.5" form factor and lesser capacity for drives of a smaller footprint. As traditional drive recording begins to reach the ceiling of magnetic properties, several technologies are on the horizon to provide storage options for the industry.
Current magnetic drives employ Perpendicular Magnetic Recording (PMR), meaning the magnetic bits align perpendicularly to the spinning disk. Since PMR began shipping into commercial applications in 2005, storage densities have increased as much as eight times from the previous standard, longitudinal recording[4]. As storage demands escalate, disk capacity has grown based on areal density (AD) improvements, but the slowing of AD advances presents a dilemma: PMR is reaching its limit. An interim answer may be Shingle Magnetic Recording (SMR) technology. (According to Webopedia, areal density is also referred to as bit density and denotes the amount of data that can be packed, usually measured in gigabits/square inch, onto a storage medium. Webopedia says the term is useful when one compares different types of media, magnetic disks and optical disks, for example.)
Like shingle tiles layered on a roof, SMR writes partially overlapping data tracks in a particular direction, and that radically increases a drive's areal density, getting more tracks on disk platter surfaces. Tracks are written with a write head wider than the track pitch, thus improving overwrite and adjacent track interference. SMR may help extend PMR by 20 to 50% over conventional recording, but SMR has its own issues associated with emulating the host random read/write commands as random read/sequential write operations on the media. An ideal fit for selective functions such as archive data storage, SMR will likely remain as a technology option in combination with other enablers on a forward basis.
In HDD evolution, moving from PMR technology and the present Exchange Coupled Composite (ECC) media to Energy Assisted Magnetic Recording (EAMR) may be the next logical step. EAMR technologies apply either a high-frequency magnetic field (microwaves) or heat (via an integrated laser) to a microscopic region on the recording media to facilitate the process of writing data. Expected to enable the number of bits that can be stored on the disk to up to 5 terabits or more per square inch, EAMR technologies should come to market in the next three to five years.
Another technology under investigation is that of Bit-Patterned Media (BPM) which involves pre-defining the size and position of "islands" (bits) in the recording medium via advanced lithography processes and is expected to increase storage density on HDDs to 10 terabits/square inch when used in conjunction with EAMR. Anticipated to come to market in five to seven years, BPM records individual bits on lithographed islands of strongly coupled magnetic material which retain each bit's magnetic charge, thereby allowing the bits to be far smaller than would otherwise be possible with continuous media. Speed-bumps to BPM's implementation are significant cost and fabrication concerns.
As different storage methods come under review, what the hard drives of tomorrow will look like remains to be seen. Many variables and the possibility of new discoveries make concrete predictions impossible as vendors continue to explore and invest in a variety of technologies.
Offering the greatest value in computer storage for more than half a century, the hard drive industry will find a way to advance existing and develop new technologies to support the future needs of consumers and businesses alike.
1. Gartner Group. (Slide 9, IDEMA ASTC presentation,
http://www.idema.org/wp-content/uploads/downloads/2011/01/ASTC-Excon-Presentation.pdf).
2. IDC Study: "Extracting Value from Chaos," June 2011.
3. Mashable.com
4. Wikipedia
