Within the next six years, hard disk drives will go from 6TB of storage to 60TB. Here are the technological advancements that will make that possible.
Going from 6TB to 60TB in six years
While capacity on hard disk drives has been doubling every 12 to 18 months -- faster than Moore's Law and integrated circuits -- there is a coming sea change that will drive the capacity up 10-fold, according to hard drive maker Seagate.
While that is remarkable, past changes and recent technology breakthroughs have led us to today's 6TB data center drives and 4TB desktop drives. Data storage is among the few techological advances that has actually surpassed our current needs.
From one ton and 5MB to 1.5lbs and 6TB
It's hard to believe how far we've come.
In 1956, IBM introduced the first hard disk drive, the RAMAC 350 (Random Access Method of Accounting and Control). The RAMAC 350 had 50, 24-in. disk platters and weighed about a ton. It could store up to 5MB of data. Up until 2002, hard disk drives used the same basic technology -- only smaller.
In 2002, hard drive manufacturers changed the orientation of bits on a disk drive platter from horizontal to perpendicular. By changing the magnetic polarity of the bits and standing them on end, technologists were able to squeeze them more tightly together and increase the areal density of drive platters. More bits means more storage.
Overlapping the shingles
In 2013, Seagate began using Singled Magnetic Recording (SMR) to squeeze more data onto disks by overlapping the data tracks on them like shingles on a roof. By overlapping tracks, areal densities increased from 1.3 terabits per square inch to 1.4 terabits per square inch.
Seagate is on track this year to again improve areal density by up to 25%, or about 1.25TB per disk platter with SMR.
Helium gives drives a lift
In 2013, Western Digital subsidiary HGST released the first drive that was hermetically sealed with helium inside -- the Ultrastar He6. The new drive pushed the number of spinning platters inside from five to seven and increased areal density on each platter.
Using helium solved several problems. At one-seventh the density of air, helium reduced internal friction, so drives use 23% less power, are 30% quieter and run four to five degrees cooler than previous models. Helium also reduced humidity and other contaminates from getting into the drive and reduced "flutter," a phenominon where air flowing up and down a disk platter stack can cause read/write head positioning errors.
Adding helium to 3.5-in. drives, allowed capacity to jump by 50%.
Nanolithography and self-assembling molecules
HGST Labs announced last year that it had combined two innovative nanotechnologies -- self-assembling molecules and nanoimprinting -- to create large areas of dense patterns of magnetic islands on disk platters that are only 10 billionths of a meter (10 nanometers) wide. These features are only about 50 atoms wide and some 100,000 times thinner than a human hair.
Each dot can store a single bit of information. This pattern has 1.2 trillion dots per square inch – twice the density of today’s disk drives.
HGST expects bit-patterned media to become a cost-effective means of increasing data densities in magnetic hard disk drives before the end of the decade.
The next advance, which will take disk drives to 5Tbit/in areal density, is heat-assisted magnetic recording (HAMR). HAMR, which Seagate patented in 2006, adds a small laser to a drive to change the magnetic properties of the disk.
HAMR also uses nanotube-based lubrication to allow the read/write head of a disk drive to get closer to the surface of a spinning platter to write and read more bits of data.
A chief advance with HAMR is the switch from a cobalt platinum alloy, the coating used on today's disks for data bit recording, to iron platinum, a much stronger magnetic material that helps stabilize data bits at smaller sizes.
Seagate's first HAMR drives are expected in 2015 or 2016.
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