LD25 Series PATA Product Manual, Rev. C
2.0 Drive specifications
Unless otherwise noted, all specifications are measured under ambient conditions, at 25°C, and nominal
power. For convenience, the phrases the drive and this drive are used throughout this manual to indicate
ST9402115A and ST920217A model drives.
2.1 Specification summary
The specifications listed in this table are for quick reference. For details on specification measurement or
definition, see the appropriate section of this manual.
Table 1: Specifications
Drive specification ST9402115A ST920217A
Formatted Gbytes (512 bytes/sector)* 40 20
Guaranteed sectors 82,443,600 41,021,800
Bytes per sector 512
Default sectors per track 63
Default read/write heads 16
Default cylinders 16,383
Physical read/write heads 2 1
Discs 1 1
Recording density, BPI (bits/inch typical) 675,900
Track density. TPI (tracks/inch typical) 114,000
Areal density (Gbits/inch
2
max) 81
Spindle speed (RPM) 5,400
Internal data transfer rate OD (Mbytes/sec max) 57.6
I/O data-transfer rate (Mbytes/sec max) 100
ATA data-transfer modes supported PIO modes 0–4
Multiword DMA modes 0–2
Ultra DMA modes 0–5
Cache buffer (Mbytes) 2
Height 9.5 +/-0.2 mm (0.374 +/-.008 inches)
Width 69.85 +/-0.25 mm (2.750 +/-0.010 inches)
Length 100.2 +/-0.25 mm (3.945 +/-0.010 inches)
Weight (typical) 100 grams (0.22 lb)
Average latency (msec) 5.6
Power-on to ready (sec typical) 4.0
Standby to ready (sec typical) 3.0
Track-to-track seek time (msec typical) 1.0 (read), 1.5 (write)
Average seek, read (msec typical) <16
Average seek, write (msec typical) <16
