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IBM and Fujifilm have demonstrated a world record in areal data density on linear magnetic tape — a significant update to one of the computer industry's most resilient, reliable and affordable data storage technologies.

This breakthrough proves that tape technology can increase capacity for years to come, which has important implications, as tape storage systems are more energy efficient and cost-effective than hard disk drive storage systems. Businesses and governments use magnetic tape to store, protect and access large volumes of important data, including: data and video archives, back-up files, replicas for disaster recovery, and retention of information required for regulatory compliance.

 The scientists at IBM Research – Zurich, in cooperation with the FUJIFILM, recorded data onto an advanced prototype tape, at a density of 29.5 billion bits per square inch — about 39 times the areal data density of today's most popular industry-standard magnetic tape product*. To achieve this feat, IBM Research has developed several new critical technologies, and for the past three years worked closely with FUJIFILM to optimize its next-generation dual-coat magnetic tape based on barium ferrite (BaFe) particles.

 These new technologies are estimated to enable cartridge capacities that could hold up to 35 trillion bytes (terabytes) of uncompressed data**. This is about 44 times*** the capacity of today's IBM LTO Generation 4 cartridge. A capacity of 35 terabytes of data is sufficient to store the text of 35 million books, which would require 248 miles (399 km) of bookshelves.

For the past several years, scientists from IBM Research – Zurich have dramatically improved the precision of controlling the position of the read-write heads, leading to a more than 25-fold increase in the number of tracks that can be squeezed onto the half-inch-wide tape. In addition, they have developed new advanced detection methods to improve the accuracy of reading the tiny magnetic bits, thereby achieving an increase in the linear recording density of more than 50 percent. Another key enabling technology for achieving the required track-follow performance in this demonstration was a new, low-friction read-write head developed by IBM Research – Almaden, which has also been collaborating with FUJIFILM to develop next-generation media.

Technical details: IBM's world-record achievement leverages notable improvements in four areas of the magnetic tape system

1. New high-density, dual-coated particulate magnetic tape: Developed by FUJIFILM in close collaboration with IBM Research scientists, this next-generation version of its NANOCUBIC(TM) tape uses a new ultra-fine, perpendicularly-oriented barium-ferrite magnetic medium that enables high-density data recording without using expensive metal sputtering or evaporation coating methods.
2. Advanced servo control technologies for ultra accurate head positioning: Three new servo control technologies have been developed by IBM Research – Zurich, leading to a more than 25-fold increase in the number of data tracks that can be squeezed onto the half-inch-wide tape:
   • a new servo pattern, enabling the generation of high-bandwidth nanometer-scale position information;
   • a new method for detecting and decoding the position information encoded in the servo pattern, and
   • advanced state-space-based control concepts that, combined with the other two technologies, culminated in the demonstration of an extremely precise track-follow performance of less than 24 nm standard deviation from the target track position.
3. These technologies were instrumental in reducing the track width to less than 0.45 micrometers.
4. Innovative signal-processing algorithms for the data channel: An advanced data read channel based on a new data-dependent noise-predictive, maximum-likelihood (DD-NPML) detection scheme was developed at IBM Research – Zurich to enable the accurate detection of the data despite the reduction in the signal-to-noise ratio resulting from the use of an ultra-narrow 0.2-µm data reader head. With this technique, which also takes the noise characteristics of FUJIFILM's BaFe medium into account, a linear density increase of more than 50 percent relative to LTO Generation 4 was achieved.
5. Low-friction GMR (giant magnetoresistive) read/write head assemblies: Two new head technologies have been developed by the tape development and research teams at IBM Research – Almaden, namely, a new reduced-friction head assembly that allows the use of smoother magnetic tapes and an advanced GMR head module incorporating optimized servo readers. These head technologies were critical for achieving the required track-follow performance mentioned above.

 

* The demonstration was performed at product-level tape speeds (2 meters per second) and achieved error rates that are correctable using standard error-correction techniques to meet IBM's performance specification for its LTO Generation 4 products.

** Note that this calculation assumes a roughly 12% increase in tape length due to the reduced medium thickness.

*** Note that this has been rounded up from 43.75 times.