IBM increased magnetic tape density 165 million times over 60 years

IBM Research scientists have achieved a new world record in tape storage – their fifth since 2006. The new record of 201 Gb/in2 (gigabits per square inch) in areal density was achieved on a prototype sputtered magnetic tape developed by Sony Storage Media Solutions.

This new record areal recording density is more than 20 times the areal density used in current state of the art commercial tape drives such as the IBM TS1155 enterprise tape drive, and it enables the potential to record up to about 330 terabytes (TB) of uncompressed data* on a single tape cartridge that would fit in the palm of your hand. 330 terabytes of data are comparable to the text of 330 million books, which would fill a bookshelf that stretches slightly beyond the northeastern to the southwestern most tips of Japan.

Magnetic tape data storage is currently experiencing a renaissance. With this achievement, IBM scientists demonstrate the viability of continuing to scale the tape roadmap for another decade.

“Tape has traditionally been used for video archives, back-up files, replicas for disaster recovery and retention of information on premise, but the industry is also expanding to off-premise applications in the cloud,” said IBM Fellow Evangelos Eleftheriou. “While sputtered tape is expected to cost a little more to manufacture than current commercial tape that uses Barium ferrite (BaFe), the potential for very high capacity will make the cost per TB very attractive, making this technology practical for cold storage in the cloud.”

To achieve 201 billion bits per square inch, IBM researchers developed several new technologies, including:

* Innovative signal-processing algorithms for the data channel, based on noise-predictive detection principles, which enable reliable operation at a linear density of 818,000 bits per inch with an ultra-narrow 48nm wide tunneling magneto-resistive (TMR) reader.
* A set of advanced servo control technologies that when combined enable head positioning with an accuracy of better than 7 nanometers. This combined with a 48nm wide (TMR) hard disk drive read head enables a track density of 246,200 tracks per inch, a 13-fold increase over a state of the art TS1155 drive.
* A novel low friction tape head technology that permits the use of very smooth tape media

The areal density demonstration announced today represents a potential increase in capacity of 165,000,000 times compared with IBM’s first tape drive product from 60 years ago.

IEEE Transactions on Magnetics- 201 Gb/in² Recording Areal Density on Sputtered Magnetic Tape

Abstract
A prototype perpendicularly oriented sputtered tape sample was investigated using a prototype high-moment tape write head and a 48-nm-wide tunneling-magnetoresistive (TMR) hard disk drive read head. A linear density of 818 kbpi with a post-detection byte-error rate < 0.023 was demonstrated based on measured recording data and a software read channel that used an extended version of the noise-predictive maximum-likelihood detection scheme that tracks the mean of the data-dependent noise. Using a previously reported iterative decoding architecture, a user bit-error rate of less than 1e-20 can be achieved at this operating point. Track-following servo performance characterized by the standard deviation of the position error signal (σ-PES) less than 6.5 nm was also demonstrated over a tape speed range of 1.2 to 4.1 m/s. This magnitude of PES in combination with a 48-nm-wide reader enables reliable recording at a track width of 103 nm corresponding to a track density of 246.2 ktpi, for an equivalent areal density of 201.4 Gb/in².

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