This Techworld document tabulates details of the Value DLT and SuperDLT tape formats and includes road map details where available. These are entry-level and mid-range tape market products from Quantum.

DLT
Quantum initiated its Digital Linear Tape (DLT) series of products with DLT-2000, now defunct. DLT proved very popular as it developed and became a mid-range leader, displacing Mammoth in the process. Tracks are wtitten is a serpentine way parallel to the edge of the tape. The media is a half-inch wide.

The new Value DLT line replaces the relatively recent DLT formats which are listed here for reference:-

DLT-4000 DLT-7000 DLT-8000
Raw Capacity 20GB 35GB 40GB
Compressed Capacity 40GB 70GB 80GB
Raw Transfer Rate 1.5MB/sec 5MB/sec 6MB/sec
Compressed Transfer Rate 3MB/sec 10MB/sec 12MB/sec
Date available 1998 1999

The main technical difference between DLT7000 and DLT 8000 was the addition of a Ferrite head. All three formats use the same DLTtapeIV media.

In 2001 Quantum introduced its higher capacity SuperDLT drive. Over the next couple of years there was a re-positioning and development of the DLT line into a ValueDLT line which we cover next.

ValueDLT

VS80 VS160 VS320 VS600
Raw Capacity 40GB 80GB 160GB 300GB
Compressed Capacity 800GB 160GB 320GB 600GB
Raw Transfer Rate 3MB/sec 8M/sec 15MB/sec 30MB/sec
Compressed Transfer Rate 6MB/sec 16MB/sec 30MB/sec 60MB/sec
Point your browser here for a DLT roadmap. DLT VS80 and VS160 are available now. Expect VS320 in 2004 and VS600 in or around 2006. The VS80 format uses the DLTtapeIV media and is backward read-compatible with the DLT-4000 format. VS160 is backward read-compatible with VS80. VS320 will be backward read-compatible with VS160.

SuperDLT
This is Quantum's super tape offering, the one that directly competes with the various LTO Ultrium formats. Once again it is a half inch linear tape format, like the original DLT and VS-nnn formats. There are five generations on the roadmap.

SDLT220 SDLT320 SDLT600 SDLT1200 SDLT2400
Raw Capacity 110GB 160GB 300GB 600GB 1.2TB
Compressed Capacity 220GB 320GB 600GB 1.2TB 2.4TB
Raw Transfer Rate 11MB/sec 16M/sec c32MB/sec 40-80MB/sec c100MB/sec
Compressed Transfer Rate 22MB/sec 32MB/sec c64MB/sec 80-160MB/sec c200MB/sec

The availability dates are: SDLT220 - 2001; SDLT320 - 2002; SDLT600 - 2003; SDLT1200 - 2004; SDLT2400 - c2006. SDLT220 and 320 use SuperDLT 1 tape media whereas SDLT600 uses a new SDLT media. SDLT220 is no longer listed as a current format on the Quantum DLT web site. VS320 overlaps it in capacity.

SDLT 320 is backward-read and -write compatible with SDLT220, and backward-read compatible with DLT8000, DLT7000, DLT4000 and DLT VS80 using DLTtapeIV media. SDLT 600 is now available and is backward-read compatible with SDLT 320, SDLT 220 and DLT VS160 drives.

SDLT1200 and 2400 planned interfaces include Serial Attach SCSI (SAS), Ultra 320 SCSI and Fibre Channel. SDLT1200 performance is expected to be greater than 50 MB/sec native and 100 MB/sec compressed. SDLT 2400 performance is expected to be greater than 100 MB/sec native and 200 MB/sec compressed.

The next articles in this tape format series will look at the proprietary StorageTek and IBM formats.