Quantum DLT 2000 Handbook page 77

DLTtape IIIXT
DLTtape III
Figure 7-5 DLTtape Cartridges Are Color Coded
DLTtape IIIXT cartridge has a native capacity of 15GB, and the
DLTtape IV cartridge has a native capacity of 35 or 40GB.
Super DLTtape I cartridges have a capacity of 110GB.
What accounts for the difference in capacity between cartridges?
There are several factors. First and most obvious is tape length. Both
DLTtape IIIXT cartridges and DLTtape IV cartridges have a longer
tape than the DLTtape III cartridge – 1,828 feet versus 1,200 feet. As
a result of the length of tape, combined with its half-inch width, the
total tape area contained in a DLTtape IV cartridge is over 10,000
square inches. (See Figure 7-6.) That is significantly more tape area
than competitive technologies offer, creating far greater potential for
capacity growth.
DLTtape IV media has significantly different magnetic properties
that result in higher capacity. DLTtape IV media is double-coated
tape with a significantly smaller coating particle size than earlier
7.6 DLTtape MEDIA
DLTtape IV
Super DLTtape I
for easy identification.