By Dave Simpson
—At the Storage World Conference in Long Beach, CA, this week, Sony announced the fifth generation of its Advanced Intelligent Tape (AIT) technology. AIT-5 packs 400GB per cartridge uncompressed (or 1.04 TB assuming 2.6:1 compression), which is twice the capacity of AIT-4 cartridges. However, the native transfer rate remains the same as AIT-4 at a maximum of 24MBps (or 225GB per hour with 2.6:1 compression).
"AIT-5 represents a re-positioning and a change in direction for AIT," says Bob Abraham, president of the Freeman Reports research firm. "Rather than try to continue doubling the transfer rate, Sony has stepped away from the LTO-SuperDLT war—which is a smart move."
When the announcement was made, Sony's OEM partners, including Cybernetics, Qualstar, and Spectra Logic, were on hand to pledge their support for AIT-5. OEM evaluation unit shipments begin next month, with volume shipments and end-user availability expected in October.
Michael Nixon, Sony's senior manager of OEM products, says that AIT-5 will resolve the incompatibility problems that plagued AIT-4. For example, AIT-5 is read/write-compatibility with previous generations such as AIT-4, AIT-3Ex, and AIT-3. In contrast, AIT-4 drives broke the backward-compatibility chain and were only read/write-compatible with AIT-3Ex media.
AIT-5 is based on many of the standard AIT technologies, such as an 8mm tape format with helical scan recording, a 3.5-inch drive form factor, dynamic tracking, Advanced Metal Evaporated (AME) media, a Remote-Memory-In-Cassette (R-MIC) chip, and support for write-once, read-many (WORM) functionality, which prevents overwriting, altering, or erasing data. However, the AIT-5 format marks the first time Sony has used magneto-resistive (MR) heads in its tape streamer products. These heads enable the higher capacity of AIT-5.
"AIT is a new technology platform, as opposed to an evolutionary step, with new media and head technology," says Freeman Reports' Abraham, "which will make it relatively easy for Sony to move to the next generation of AIT." Sony's road map currently includes a sixth generation—AIT-6—at a native capacity of 800GB per cartridge.
Sony officials hope that the AIT-5 format will stem—at least to a degree—the declining market share that the 8mm tape format has been experiencing. For example, Freeman Reports predicts a negative 11% compound annual growth rate for 8mm tape libraries over the 2005 to 2011 time period, representing a market share drop from 4.1% to 1.3% in terms of unit shipments in the overall tape library market.
AIT-5 drives are expected to initially be available with SCSI interfaces, with support for other interfaces to follow.