Advanced Intelligent Tape (AIT) is a discontinued high-speed, high-capacity magnetic tape data storage format developed and controlled by Sony. It was introduced in 1996 to utilise Advanced Metal Evaporated (AME) technology. It competed mainly against the DLT, LTO, DAT/DDS, and VXA formats. AIT uses 8mm tape in a cassette similar to Video8. Super AIT (SAIT) is a higher capacity variant using wider half inch (1/2") tape in a larger, single-spool cartridge. Both AIT and SAIT use the helical scan method of reading and writing to the tape.
AIT tapes.
Form factors
AIT technology was available in two form factors.
AIT – 8 mm, dual reel cartridge, similar to Sony's 8 mm videotape products and Exabyte's 8 mm data tape products.
SAIT – 1/2", single reel cartridge, similar to DLT and LTO.
In March 2010, Sony announced the discontinuation of the AIT product line, and renewed collaboration with Hewlett-Packard on further development of the DDS tape format,[1]
Compatibility
One of the most compelling features of the AIT format is that many generations are both backwards and forwards compatible. This allows multiple generations of tape drives to both read and write to multiple generations of tape media.
AIT generations
Generation
AIT-E Turbo
AIT-1
AIT-1 Turbo
AIT-2
AIT-2 Turbo
Release Date
2004
1996
2004
1999
Native Capacity (GB)
20
25, 35
40
36, 50
80
Max Speed (MB/s)
6
3, 4
6
6
12
Encoding
Trellis-coding for Partial Response (TCPR)
RPM
4800
6400
Tape Length (m)
98
170, 230
186
170, 230
186
Tape Thickness (μm)
6.6
7.0, 5.3
6.6
7.0, 5.3
6.6
AIT-1
Original specification's data capacity up to 25 GB native and up to 65 GB compressed, with a data transfer speed of 3 MB/s.
Extended length tape, introduced in 1999 gave additional capacity, 35 GB.
Speed increased to 4 MB/s in 2001.
Turbo variant, introduced in 2004, is 50% faster (6 MB/s) and holds 40 GB.
A budget version, AIT-E Turbo, was also introduced in 2004 to compete with DDS.
Comparison of "supertape" capacities, including SAIT.
Generation
SAIT-1
SAIT-2
SAIT-3
SAIT-4
Release Date
2003
2006
cancelled
cancelled
Native Capacity (GB)
500
800
2000
4000
Max Speed (MB/s)
30
45
120
240
Tape Length (m)
600
640
Tape Thickness (μm)
8.6
SAIT-1
Highest capacity tape cartridge from 2003 to 2006. Displaced by DLT-S4 (800 GB).
The AIT format was developed and is controlled by Sony.
SAIT-2
Released in 2006 by Sony, available only in libraries, 800 GB native and 45 MB/s sustained transfer rate.[3]
Notes
Data Capacity and Speed figures above are for uncompressed data. Sony assumes a 2x or 2.6x compression factor in their marketing material.
According to Sony, "All future products are based on technology projections."
Technical features
AME
Advanced Metal Evaporated is a different formulation of tape media.
MIC
Memory-in-Cassette
is a 16-64KB memory chip in the cartridge that keeps relevant information about the data on the tape to allow quicker access. The drive did not have to read the whole tape until it came across the file required like a file index.
R-MIC
Remote - Memory in Cassette
Like MIC except it does not require physical contact.
