Quantum DLT 2000 Handbook page 69

Figure 6-2 A Gentle Tape Path
stress and wear resulting in industry-leading tape life of up to
1,000,000 passes.
ally use far lower figures. A DLTtape drive lays down data in a series of
parallel tracks that run the length of the tape. As a result, it takes multi-
ple passes to read or write the same amount of data on DLTtape media
that should be read or written in a single pass on competitive drives.
In general, a four-channel DLT 8000 drive will need 52 passes to
cover 208 tracks. If you divide 1,000,000 passes by 52, you get a figure
of 19,230 head passes. Durability figures for some competitive units
are in the range of 1,500 passes. Which still makes the DLTtape sys-
tem more than 10 times more durable, even after adjusting for the
difference in technology. (This is the worst case scenario for DLTtape
recording. In operation, it is unlikely to require 52 passes to retrieve
the requested data in a typical cartridge usage, as only a small part in
the tape will be read in most cases.) Again, this big advantage is based
on the basic design of the drive: the tape goes over the heads with
minimal tension (see Figure 6-2), and the heads are stationary while
reading and writing. Wear and tear on the tape is dramatically less
6.6 DEMYSTIFYING TAPE DRIVE SPECS
in all DLTtape drives reduces