IBM sets new disk-drive world record

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SAN JOSE, California - 12 May 1999: -- IBM has set a new world record in hard-disk data-storage density, writing and reading data bits so small that an unprecedented 20 billion of them would fit within a square inch.

"This laboratory demonstration is very good news for our customers and the data storage industry," said Robert Scranton, director of recording head technology at IBM's Almaden Research Center in San Jose, Calif. "It shows that disk-drive capacities will continue to increase well into the 21st century. This trend will enable new capabilities for portable electronics that use IBM's tiny 1-inch microdrive or portable computers with our industry-leading 2.5-inch drives, give desktop users rapid access to huge multimedia files and permit large corporations to store much more data in the same floorspace."

The new record density of 20 gigabits per square inch (3.1 gigabits per square centimeter) is more than three times that of any disk-drive product shipping today. At this density, every square inch of disk space could hold 2.5 gigabytes -- equivalent to two TV-quality movies, two hours of MPEG-2 digital video, nearly the contents of 4 CD-ROMs or the text of some 2,500 average-sized novels.

Since 1991, when IBM introduced the industry's first magnetoresistive (MR) sensor for reading data on hard disks, data density has increased at greater than 60 percent a year. If that rate continues, 20-gigabit-density products would be available within three years. Over the past eight years, the average data-storage capacity of disk drives sold worldwide has increased more than 50-fold, while the price per gigabyte of such capacity has dropped nearly 300-fold.*

Increasing data density can also lead to disk drives that are lighter and consume less energy -- important factors in portable computers. In addition, these products tend to be more reliable, because fewer disks are needed to achieve a given data-storage capacity.

"To make smaller bits that will still store data reliably, we must improve the disk materials and read/write components in a way that the bits can be quickly erased and rewritten, but that their magnetic orientations will not change by themselves," Scranton added. "The stability of the bits in this demonstration was especially encouraging."

The 20-gigabit density milestone was achieved by a team of scientists and engineers from IBM's Storage Systems Division, which develops, manufactures and sells data-storage products. This demonstration is part of its long-standing collaboration with IBM Research to understand and advance magnetic data storage technologies.

As in its previous record-density demonstrations of 1-, 3-, 5- and 10- gigabits per square inch (announced in December 1989, March 1995 and December 1996 and December 1997, respectively), IBM achieved product-level reading and writing accuracy at realistic data rates. The 20-gigabit demonstration used an advanced version of the giant magnetoresistive (GMR) read head -- the most sensitive sensor for reading magnetic bits on disks -- a narrow-track thin-film inductive write head, ultra-low-noise cobalt-alloy magnetic media and an advanced PRML (Partial-Response, Maximum Likelihood) channel electronics. Some 490,000 bits per inch were written along the concentric tracks packed at a density of 41,400 per radial inch. The bits were written and read at data rates of 18 million bytes per second. The on-track data was read essentially flawlessly, with an uncorrected rate of less than one error in a 100 million bits, which in products would be reduced by error-correcting codes to less than one in a trillion. The latter figure is equivalent to transcribing more than 1,000 years of a daily newspaper before making a single error.

The first technical details of this demonstration will be disclosed next week at the International Magnetics Conference (Intermag 99) in Kyongju, Korea.

The IBM home page is at: For more information about IBM hard drives, see . Details on the achievements of IBM Research scientists can be found on the IBM Research home page: .

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*Average disk-drive capacity in 1991: 0.145GB 1999: 7.7 GB (53x)

Average disk-drive cost/MB in 1991: $5,230/GB 1999: $18.42/GB (284x) (Source: Industry analyst reports)

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