IBM Researchers Set World Record in Magnetic Tape Data
Density; 6.67 Billion Bits Per Square Inch Lays Foundation for Future Tape
The researchers at IBM's
Almaden Research Center in San Jose, Calif., packed data onto a test tape at a
density of 6.67 billion bits per square inch -- more than 15 times the data density of today's most popular industry standard magnetic
tape products. To achieve this feat they created several new data-recording technologies and
worked with Fuji Photo Film Co., Ltd. of Japan to
develop a next-generation dual-coat magnetic tape capable of storing high-density data.
The demonstration shows that magnetic tape data storage should be able to
maintain its cost advantage over other technologies for years to come. When
these new technologies and tape become available in products - projected to be
in about five years - a cartridge the size of an industry-standard Linear Tape
Open (LTO) tape cartridge could hold up to 8 trillion bytes (terabytes) of
uncompressed data. This is 20 times the capacity of today's LTO-Generation 3
cartridge, which is about half the physical size of a VHS videocassette. Eight
terabytes of data is equivalent to the text in 8 million books, which would
require 57 miles of bookshelves.
"Today's announcement tells our customers that IBM has the technology to
continue to improve its tape products to address their growing needs for
affordable and robust data storage," said Cindy Grossman, vice president, IBM
Tape Storage Systems. "With analysts projecting tape automation revenue to grow
8 percent annually through 2011, our customers are storing increasing amounts of
data to manage their enterprises and to address the compliance requirements of
laws such as the Sarbanes-Oxley Act of 2002 and the Health Insurance Portability
and Accountability Act of 1996. Greater data density and cartridge capacity
enables them to store more data in less space, helping to keep magnetic tape as
the most cost-effective form of data storage."
Businesses use magnetic tape to store large volumes of important data that
are used infrequently or don't require sub-second access times. These uses
include data archives, backup files, replicas for disaster recovery and
retention of information required for regulatory compliance. Such data are often
contained within automated tape libraries where one or more read-write units
service dozens to thousands of tape cartridges. High-end tape libraries can thus
store petabytes - millions of gigabytes - of information. On a per-gigabyte
basis, tape systems are currently about one-fifth to one-tenth the cost of
today's hard-disk-drive storage systems, depending on their size. Moreover, tape
cartridges consume no energy unless they are being accessed - unlike spinning
disks, which need occasional use to remain operational - providing another area
of potential cost savings.
IBM's record-breaking demonstration trumped its 2002 recording of a terabyte
of date onto a single 3592-sized cartridge at a density of 1 billion bits per
square inch. Over the past two years, Almaden researchers worked closely with
Fuji Photo Film Co., Ltd., engineers on the development of a new dual coat
magnetic tape media capable of high-density recording. The Almaden researchers
also developed technologies to dramatically improve the capabilities of
read-write heads and the methods for positioning the heads and handling the tape
to enable data tracks one-tenth as wide as in current products. Scientists from
IBM's Zurich Research Laboratory developed a new coding method that improved the
accuracy of reading the tiny magnetic bits.
"This demonstration confirms IBM's continued leadership in magnetic tape
technology," said Spike Narayan, senior manager of advanced technology concepts
at IBM Almaden. "This is a major milestone in our program and gives magnetic
tape the density boost that we gave hard-disk drives in the 1990s."
IBM has a long history of innovation in magnetic tape data storage. Its first
commercial tape product, the 726 Magnetic Tape Unit, was announced 54 years ago
next week. It used reels of half-inch-wide tape that each had a capacity of
about 2 megabytes. In 2002, IBM demonstrated data capacity 500,000 times greater
in its 1-terabyte cartridge demonstration. According to IDC, IBM was the 2005
revenue leader in the $4.82 billion worldwide branded tape drive and tape
library automation marketplace.
IBM's world-record achievement leverages notable improvements in five areas
of the magnetic tape system:
New high-density dual-coated particulate magnetic tape: Developed by Fuji
Photo Film Co., Ltd., in Japan in collaboration with IBM Almaden researchers,
this next-generation version of its NANOCUBIC(TM) tape uses a new barium-ferrite
magnetic media that enables high-density data recording without using expensive
metal sputtering or evaporation coating methods.
More sensitive read-write head: For the first time, magnetic tape technology
employs the sensitive giant-magnetoresistive (GMR) head materials and structures
used to sense very small magnetic fields in hard disk drives.
GMR servo reader: New GMR servo-reading elements, software and
fast-and-precise positioning devices provides an active feedback system with
unprecedented 0.35-micron accuracy in monitoring and positioning the read-write
head over the 1.5-micron-wide residual data track..
Improved tape-handling features: Flangeless, grooved rollers permit smoother
high-speed passage of the tape, which also enhances the ability of the head to
write and read high-density data.
Innovative signal processing algorithms for the read data channel: An
advanced read channel used new "noise-predictive, maximum-likelihood" (NPML)
software developed at IBM's Zurich Research Laboratory to process the captured
data faster and more accurately than would have been possible with existing
The demonstration was performed at product-level tape
speeds (4 meters per second) and achieved error rates that should be
correctable, using advanced error-correction techniques, to meet IBM's
specification for its LTO-3 products.