These backup solutions can be purchased and used with little or no modification and managed by someone with moderate technical expertise. Tape drives have the highest upfront hardware cost, but they offer the most storage space. DVDs and CDs offer a lower upfront cost, but with considerably less storage capacity. DVDs and CDs are more appropriate for backing up important sets of files rather than an entire computer system. Generally, data compression doubles the native capacity.
Compression also doubles the data transfer speed.
There is a wide variety of magnetic tape technologies with different capacities and features, and new technologies are coming out all the time. These DAT drives use 4 mm tape cartridges that look like small audiocassettes. DAT tapes were originally designed to hold CD-quality audio, but caught on only with professional musicians, not consumers. DAT drive- and tape storage capacity and transfer speed depend on which generation of DDS they support. DLTs are used primarily by medium to large-size businesses and have a longer tape and head life than other tape drive technologies.