DDS

DDS

Digital Data Storage, also known (incorrectly) as DAT or 4mm tape or drive. cf DLT. Tape capacities vary:

Type		Tape length	Native capacity 1	Notional capacity 2
DDS-1	DDS-60	60m	1.3GB	2.6GB
	DDS-90	90m	2GB	4GB
DDS-2	DAT 8	120m	4GB	8GB
DDS-3		125m	12GB	24GB
DDS-4		150m	20GB	40GB
DDS-5	DAT 72	170m	36GB	72GB

Notes:

1. Native capacity is the amount of data that can be stored on the tape with no compression applied.
2. Notional capacity (which is normally how vendors tend to rate the tapes and drives) assumed hardware compression of 2:1, but this will vary with real data.

For more information see:

• www.dds-tape.com - DDS Manufacturer's group web site.
• DAT or DSS? (archived)
• http://everything.explained.at/Digital_Data_Storage/ - Digital Data Storage (DDS) explained.