Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
53
13
Acoustics
13.1
Sound Power Levels
The upper limit criteria of A-weighted sound power levels are given in Bel, relative to one pico watt, and are shown in
the following table. The measurement method is in accordance with ISO-7779.
Table 26 A-weighted Sound Power Levels
Model Mode
A-weighted Sound Power Level (Bel)
Typical Maximum
1200 GB Idle 3.2 3.4
Operating 3.8 4.1
Background power levels of the acoustic test chamber for each octave band are to be recorded. Sound power levels
are measured with the drive supported by spacers so that the lower surface of the drive is located at a height of 25
cm from the chamber floor.
No sound-absorbing material shall be used. The acoustical characteristics of the drive subsystem are measured
under the following conditions.
Idle Mode:
Powered on, disks spinning, track following, unit ready to receive and respond to host commands.
Operating Mode
Continuous random cylinder selection and seek operation of the actuator with dwell time at each cylinder. Seek rate
for the drive is calculated per the formula below:
Ns = average seek rate in seeks/sec where:
Ns = 0.4 / (Tt + Tl)
Tt = published random seek time
Tl = time for the drive to rotate by half a revolution