In August 1995 NEC announced the DSE1340A and DSE2010A ATA 3.5-inch magnetic disk units and the DSE1340S and DSE2010S SCSI 3.5-inch magnetic disk units. All four models featured the industry’s highest storage capacity of 670 MB per disk. To increase the units’ storage capacity, NEC used PRML, a demodulation method that raises the head density and read efficiency. NEC achieved the highest available data transfer speeds — 16.6 MB per second — and read / write speeds — 10 MB per second — at the time by using PIO Mode 4, a high-speed external interface. And highly reliable disk array systems could be constructed because of a spindle synchronization function that ensured data reads and writes were in sync when using multiple disk units simultaneously. A variety of computer products were supported by providing ATA interface models for installation in personal computers and SCSI interface models for large-scale system construction.
| Storage capacity [MB] | 1,340 / 2,010 |
|---|---|
| Average seek time [ms] | 11 |
| Average rotational latency [ms] | 6.6 |
| Data transfer speeds [MB/s] Read / write speed Host transfer speed |
5 ー 10 16.6（PIO） 13.3（DMA） |
| Disk diameter [inches] | 3.5 |
| Number of disks | 2 or 3 |
| Number of data recording heads | 4 or 6 |
| Read/Write cache（KB） | 64/64 |
| Disk rotational speed [rpm] | 4,500 |
| Recording density [bytes/inch] | 107,000 |
| Track density [tracks/inch] | 4700 |
| Recording format | 8-9PRML |
| Overall external dimensions [mm] | 101.6 x 146 x 25.4 (w x d x h) |
