Seagate ST9500320AS, ST9640320AS, ST9640322AS Drive specifications, Specification summary table

3.0Drive 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 the Momentus models.

3.1Specification summary table

The specifications listed in this table are for quick reference. For details on specification measurement or defi- nition, see the appropriate section of this manual.

Table 1: Drive specifications for 640, 500 and 400GB models

Drive specification	ST9640322AS	ST9640320AS	ST9500320AS	ST9400321AS
Formatted GB*	640		500	400
guaranteed logical blocks	1,250,263,728		976,773,168	781,422,768
bytes per physical sector	4096	512	512	4096
Physical read/write heads	4
Discs	2
Cache (MB)	8
Recording density in BPI (bits/in avg)	1560k
Track density TPI (tracks/in avg)	325k
Areal density (Gb/in2 avg)	507
Spindle speed (RPM)	5400
Average latency (ms)	5.2
Internal transfer rate (Mb/s max)	1175
I/O data transfer rate (MB/s max)	300
ATA data-transfer modes supported	SATA 1.0, Serial ATA Revision 2.6
	PIO modes 0–4
	Multiword DMA modes 0–2
	Ultra DMA modes 0–6
Height	9.5 +/- 0.2 mm (0.374 +/-.008in)
Width	69.85 mm +/- 0.25 mm (2.75 +/- 0.010in)
Length	100.35 + 0.20 / - 0.25 mm (3.951 + 0.008 / - 0.010in)
Weight	<100 g (0.220 lb)
Power-on to ready (sec typical)	3.6
Power-on to ready (sec max)	4.5
Standby to ready (sec typical)	2.5
Standby to ready (sec max)	3.5
Track-to-track seek time, read (ms typical)	1.5
Average seek, read (ms typical)	13.0
Full-stroke seek, read (ms max)	27.0
Startup current, +5V (max)	1.0A

4 Momentus Product Manual, Rev. D