NEC announced the N7797 large-volume magnetic hard disk unit along with the ACOS System 3900 in March 1991. The N7797 contained up to 32 five-inch head disk assembly (HDA) spindles. Despite being the first large-volume hard disk unit to use the smaller five-inch-diameter disks, it still utilized advanced technologies — such as a thin-film magnetic head and thin-film (plated) magnetic disk media — for a smaller footprint, higher storage densities, and faster data transfers. The N7797 was also designed to reduce installation space, power consumption, and radiated heat.
| Storage capacity per spindle [GB] | 1.53 |
|---|---|
| Average seek time [ms] | 12 |
| Average rotational latency [ms] | 5.6 |
| Data transfer speed [MB/s] | 4.5 |
| Disk diameter [inches] | 5 |
| Disk diameter [inches] | 32 |
| Unit’s total storage capacity [GB] | 49 |
| Unit’s external dimensions [mm] | 775 x 900 x 1,560 (w x d x h) |
