NEC announced the D2713 thin-profile 2.5-inch magnetic disk unit in September 1994. The unit was only 12.5 millimeters thick, weighed just 140 grams, and had a formatted capacity of 352 MB, which was perfect for notebooks and other portable computers. The D2713 featured fast access times: the average read time was 14 milliseconds, the average write time was 15 milliseconds, the media data transfer speed was 4.4 MB per second, and the transfer speed to the host was 10.6 MB per second. It also had a large 128 KB cache memory for high end-to-end computer processing performance.
| Storage capacity [MB] | 352 |
|---|---|
| Average seek time [ms] Read Write |
14 15 |
| Average rotational latency [ms] | 7.5 |
| Data transfer speed [MB/s] Media transfer speed Interface transfer speed |
4.4MAX |
| Disk diameter [inches] | 2.5 |
| Number of disks | 2 |
| Number of data recording heads | 4 |
| Disk rotational speed [rpm] | 4000 |
| Recording density [bytes/inch] | 74700 |
| Track density [tracks/inch] | 3670 |
| Recording format | 1-7RLL |
| Cache size [KB] | 128 |
| Weight [grams] | 140 |
| External dimensions [mm] | 70 x 100 x 12.5 (w x d x h) |