【Hitachi】 H-65A1/H-65A5 Disk Array Units

The H-65A1 and H-65A5, announced by Hitachi in June 2000, were the world’s largest and fastest disk array subsystems and supported large-scale SAN environments and storage consolidation that integrated data to enable higher-order use of information. The H-65A1 and H-65A5 featured connectivity with open systems and mainframes from many different vendors.

Features of the H-65A1 / H-65A5:

• （1）The disk array subsystems were expandable to 32 fiber-channel ports, twice the number on the previous model, and used a hierarchal star network to boost their internal transfer speeds to as high as 6.4 GB per second, about eight times that of the previous model.
• （2）The subsystems could accept up to 32 processors per controller, twice the number on the previous model, for a total of 64 microprocessors. This ensured high throughput while multiplexing in large-scale multiport environments.
• （3）Each controller’s cache memory could be expanded up to 32 GB, twice that of past models. The controllers supported dynamic cache residency (DCR), which continually keeps certain data in cache memory, so that the cache hit ratio for that data was always 100 percent.
• （4）The maximum storage capacity of the subsystems was 27 terabytes, about four times that of the previous models. It was also possible to mix 18, 47, and 73 GB disk drives in the subsystems for a larger span of storage capacities to meet each specific system’s requirements.