Hitachi HDS721050CLA362 - Table 28 Sound Power Levels; Acoustics

HITACHI Deskstar & CinemaStar 7K1000.B & Deskstar E7K1000 Hard Disk Drive specification
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6.7 Acoustics
The upper limit criteria of the octave sound power levels are given in Bels relative to one picowatt and are shown
in the following table. The sound power emission levels are measured in accordance with ISO 7779.
Mode
Typical / Max
1 disk model
2 disk model
3 disk model
Idle
2.5 / 2.7
2.4 / 2.5
2.7 / 2.8
Operating
Performance seek mode
N/A
2.9/ 3.1
3.1 / 3.3
Quiet seek mode
2.7 / 3.0
2.5 / 2.7
2.8 / 3.0
( ) : Generic version : Typical only, No MAX specification
Table 27 Sound power levels
Mode definition:
Idle mode. The drive is powered on, disks spinning, track following, unit ready to receive and respond to
interface commands.
Operating mode. Continuous random cylinder selection and seek operation of the actuator with a dwell
time at each cylinder. The seek rate for the drive is to be calculated as shown below:
 Dwell time = 0.5 x 60/RPM
 Seek rate = 0.4 / (Average seek time + Dwell time)