Quantum dlt 2000 User Guide

DEMYSTIFYING TAPE DRIVE SPECS

which ones you can ignore. Figure 6-1 includes the most impor-
tant specifications for the DLTtape drives.

Capacity and Data Compression
Some manufacturers specify capacity in native mode. Others list
capacity with an asterisk, and a footnote that says something like
“assumes 2:1 compression.” Sometimes you might see a figure
without an asterisk, but that figure could still very well assume
compression of three or four to one.

Compression is the result of applying a compression algorithm to
the data before it is written to the tape. For a lot of applications,
compression is standard operating procedure. However, compres-
sion is only relevant if you actually compress your data, which you
may or may not want to do. Big blocks of text can be squeezed down