The AIT format was one of the few new mid-range tape technologies introduced to address, not only a new position in capacity and performance, but also access to data. Although the key benefits of the AIT technology are described within the outstanding capacity and performance features of its highly scalable roadmap, the AIT Memory-in-Cassette (MIC) architecture was introduced to provide new capabilities such as fast time to data, data partitioning utilizing multiple load points, and a new "Write-Once-Read-Many" feature.
The AIT recording technology today offers uncompressed capacities including 25GB, 35GB, 50GB and 100GB, while showing scalability to a 6th generation product with an uncompressed capacity of up to 800GB (up to 2TB compressed!)—all using the compact 8mm cartridge form-factor. The higher compression specifications for capacity and performance for the AIT family are achieved through the incorporation of the Adaptive Lossless Data Compression (ALDC) technology, which delivers an average 2.6 to 1 compression ratio—significantly more than some competing products.
The high data search rates are achieved through the assistance of MIC technology, which provides greater intelligence to a tape drive and media combination through the use of an "auxiliary" flash memory chip incorporated into the data cassette. The MIC chip contains key parameters such as a tape log, search map, and application information that allow flexible management of the media and its contents.
Both tape drive and media are designed for long life. Since the AIT format is based on helical-scan recording utilizing Advanced Metal-Evaporated Media with its pure metal magnetization layer and protective "diamond-like carbon coating" (DLC), a much higher recording density can be implemented. Additionally, the low tape speed and low tape tension mean a gentle handling of the media over the recording heads, promoting both higher mechanism and media life. In addition, since helical-scan recording does not require fast tape speeds, the "re-positioning" time of the drive is much faster than linear serpentine technologies, providing better performance over a wide range of host data rates. Helical-scan also eliminates the need of linear technologies to "serpentine" the tape (moving back and forth hundreds of times) in order to fill the cartridge with data, but rather uses only one pass from end-to-end in order to read or write the entire cassette. Due to the low Field failure experience (less than 3.5% overall return rate) and the performance during On-going Reliability Testing (ORT), the AIT-1 and AIT-2 drives have a demonstrated reliability specification of 300,000 hours at 100% duty cycle.
As the first member of the AIT family, the AIT-1 provides 35GB of native capacity (90GB compressed), and a sustained native transfer rate of 4MB/s (10MB/s compressed) with an Ultra-SCSI LVD interface. The AIT-1 provides the entry point into the AIT family and is ideally positioned to provide a migration opportunity for DDS customers that require more capacity and performance than what DDS can deliver. Also, in order to provide the highest level of customer investment protection, media recorded by the AIT-1 drive can be read or written by each of the current AIT members, namely AIT-2 and AIT-3.
AIT-2 delivered on the promise of expanding the AIT architecture from its initial offering while maintaining the innovative 3.5" form factor. The increase in capacity and speed was achieved through technological advances in recording heads, channel coding, as well as media formulation. The AIT-2 is fully backwards compatible with AIT-1, and offers data transfer rates of 6MB/s (15MB/s compressed), while reading or writing 50GB of native capacity (130GB compressed). The AIT-2 has been shipping to customers since early 1999 and provided among the highest capacity and performance specifications for mid-range applications at its introduction. Since then, it has been extensively used in tape automation and other applications and proven itself as a robust design, capable of operating reliably in high duty-cycle environments.
By utilizing the flexible MIC architecture and expanded drive firmware, the current AIT-2 drive was modified to provide a new recording feature and benefit to customers requiring an extra level of data protection. AIT-2 WORM features secure data archiving in a write-once, read-only format with up to 130GB compressed capacity and a 15MB/s transfer rate (compressed). A specific WORM media cassette was created that incorporates a specially encoded MIC chip to communicate with the AIT-2 drive and ensure that recorded data is never erased or altered. As a result, the AIT-2 WORM drive is a true "multi-function" tape drive that accommodates both the WORM media and also standard AIT media.
AIT-3 is the third generation AIT technology implementation, doubling the capacity and performance of the prior generation. AIT-3 is fully backward read and write compatible with all AIT-2 and AIT-1 media, and offers a native capacity of 100GB (260GB with compression) and a native data transfer rate of 12MB/s (31MB/s compressed) in a compact 3.5" form-factor. The increased capacity of AIT-3 was obtained by doubling the number of recording tracks per inch of tape compared to the AIT-1 and AIT-2, while the doubling of the data transfer rate was achieved by simultaneously utilizing 2 recording heads on-tape. The AIT-3 continues the AIT reputation of providing the best capacity and performance within a 3.5" form-factor, while the compact 8mm media size allows AIT-3 automation solutions to be one of the highest density and most cost-effective available in the market.
