History (1993): IBM 3390-9 DASD 2X Cheaper but Slower

On May 18, IBM Corp. will announce a new gen of DASDs for mainframes, the 3390 Model 9, unveiled ComputerWorld in its April 12 issue.

Compared to the 3390 Model 3, produced since 1991, the price/MB should be close to 2X less. Capacity ought to triple (around 100GB per string), but also access time, which seems quite penalizing and will restrain these new disks to the storage of infrequently used data. Average access time for 3390-3 was 15ms, already higher than on former model 1 (9.5ms) and 2 (12.5ms). Model 9 seems to fit between the actual 3390 and optical disks, like an intermediate and extra storage structure operating through SMS.

Nick Allen, an analyst of the Gartner Group, concludes briefly: “The Model 9’s job is to put a floor on pricing, and IBM hopes they never sell one.”

This article is an abstract of news published on the former paper version of Computer Data Storage Newsletter on issue 64, published on May 1993.