FUTURE TAPE TECHNOLOGY

NSIC's targets for the years 2002 and 2007 are listed in Table 4.1 along with actual specifications for existing products as of 1997. The assumption is that multi-track magnetoresistive thin film heads will be used in both linear and helical formats to achieve the required density and data rates.


Fig. 4.1. Storage subsystem cost trends.

Table 4.1
Tape Density Projections

Year

Linear Bit Density (kbpi)

Track Density (tpi)

Volumetric Density Terabytes/in3

 

Linear

Helical

Linear

Helical

Helical

 

1997

100.00

120.00

750

2,800

-

<0.2

2002

200.00

200.00

6,000

6,000

6,000

0.9

 

(25 dB @ 100 kcfi)

       

2007

300.00

300.00

20,000

--

20,000

4.7


Source: NSIC, May 1998. Used by permission.

Further, by 2007, both formats will have the same volumetric density of ~5 terabytes/in3. Clearly, the projections show that most of the improvement, particularly in longitudinal recorders, will come from significantly increased track density. The increases in linear density are not inconsistent with the historical data although there has been a flattening-off since approximately 1995. It is also required that the tape thickness be reduced to about 4 µm while still maintaining sufficient mechanical properties to be transported reliably.

The various components of a tape storage system are shown in Table 4.2 with an indication of the relative position of the United States and Japan. Head technology and system electronics will be derived from hard disk drive (HDD) development but new media, improved head/tape tribological properties, reliable tape transports and new systems must come from the tape industry.

Table 4.2
Requirements for 4.7 Terabyte/in3

Requirements

World Leader

From HDD Development

  • Multi-track GMR heads in both linear and helical systems to achieve media noise-limited SNR (Sony, Yamaha)*
  • Electronics including EPR4 channel combined with (O,K) codes
  • U.S./Japan
  • U.S.

From Tape Development

  • New media (Fuji Film)*
  • Head-media tribology (Sony)*
  • Fundamental understanding of tape mechanics and transport (Sony)*
  • System development (Sony, Matsushita)*

  • Japan
  • Japan
  • U.S./Japan
  • U.S./Japan
*WTEC Visits
Published: June 1999; WTEC Hyper-Librarian