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5. Summary

The technological trends in high capacity media are increased areal density combined with faster data transfer rates. However high areal densities alone are not a measure for success - optical disk's historic lack of standards and high costs contributed to it's limited popularity. These issues have now been addressed with the growing popularity of the DVD specifications and products.

The magnetic tape products under discussion can again be split into groups orientated around data transfer rate; and hence cost of technology. Products such as DLT, Exabyte Mammoth-1, DAT DDS-4, Sony AIT-2 with data transfer rates up to 3MB per second offer good low-cost back-up for workstations and small networks. Products such as SuperDLT, Mammoth-2 and DLT-8000 are aimed at the mid-range systems and larger LAN / WAN environments, but due to the limited data transfer rate cannot yet be considered as a suitable media for a high volume data archive.

Companies with large archives and/or companies who require fast near-line access to at least some of their data may be considering four types of high-capacity media - DD-2, 3590, Ultrium or emerging products such as DTF (as compared in Table 5).

Table 5 : Summary D2, DTF, 3590, Ultrium and 3490E

Device

Recording Technology

Media Capacity (GB)

Media
Volume
(IN3)

Media Capacity/ Volume (IN3/GB)

Form Factor

Data Transfer Rate (MB/Sec)

Ampex DST-310 (D2)

Helical -19mm

50 (small Cassette)
330 (large Cassette

37.8
151.9

1.32
2.17

D2
D2

20

Sony DTF-2

Helical -19mm

200

148.6

1.35

DTF

24

IBM 3590 (Magstar)

Longitudinal - 1/2"

20

20.8

0.96

3480/90

14

IBM 3580 Ultrium

Longitudinal - 1/2"

100

20.8

4.80

3480/90

15

3480
3490
3490E

Helical - 1/2"

0.2
0.4
0.8

20.8

0.0096
0.019
0.038

3480/90

3

3590 and 3580 cartridges both share the popular 3480/3490 form factor in use by many Automated Library Systems in the oil and exploration industry, whereas the three capacities of D2 cassette are completely different physical sizes. DTF also based on Digital Betacam technology offers a unique form factor.

Longitudinal recording (3590) is considered to be better suited to "stop/start" recording applications as is necessary for oil exploration data, hence 3590 is by far the most popular for acquisition of new data. It is this together with IBM's reputation and continued dedication to solution delivery in the oil and exploration industry that is establishing the Magstar drive as the de facto standard inclusion in any organisation's high capacity data management strategy.


Table of Contents

  1. Introduction
  2. Longitudinal Recording Technology
  3. Helical Scan Technology
  4. Optical Technology
  5. Summary
  6. The Future

See other technical papers.

 


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