Vibration; Acoustics; Test For Prominent Discrete Tones (Pdts) - Seagate BARRACUDA ST31000524AS Product Manual

Drive Specifications
500, 320, 250 and 160GB models
The non-operating shock level that the drive can experience without incurring physical damage or degradation in
performance when subsequently put into operation is 350 Gs based on a non-repetitive half-sine shock pulse of
2-ms duration.

2.9.6 Vibration

All vibration specifications assume that the drive is mounted securely with the input vibration applied at the drive
mounting screws. Vibration may be applied in the X, Y or Z axis.
2.9.6.1 Operating vibration
The maximum vibration levels that the drive may experience while meeting the performance standards specified
in this document are specified below.
2Hz to 22Hz 0.25 Gs (Limited displacement)
22Hz to 350Hz 0.50 Gs
350Hz to 500Hz 0.25 Gs
2.9.6.2 Non-operating vibration
The maximum non-operating vibration levels that the drive may experience without incurring physical damage or
degradation in performance when subsequently put into operation are specified below.
5Hz to 22Hz 3.0 Gs (Limited displacement)
22Hz to 350Hz 3.0 Gs
350Hz to 500Hz 3.0 Gs

2.10 Acoustics

Drive acoustics are measured as overall A-weighted acoustic sound power levels (no pure tones). All
measurements are consistent with ISO document 7779. Sound power measurements are taken under essentially
free-field conditions over a reflecting plane. For all tests, the drive is oriented with the cover facing upward.
For seek mode tests, the drive is placed in seek mode only. The number of seeks per second is
defined by the following equation:
Note
(Number of seeks per second = 0.4 / (average latency + average access time
Table 6 Fluid Dynamic Bearing (FDB) motor acoustics
All models
*During periods of drive idle, some offline activity may occur according to the S.M.A.R.T. specification, which may increase acoustic and power
to operational levels.

2.10.1 Test for Prominent Discrete Tones (PDTs)

Seagate follows the ECMA-74 standards for measurement and identification of PDTs. An exception to this
process is the use of the absolute threshold of hearing. Seagate uses this threshold curve (originated in ISO 389-
7) to discern tone audibility and to compensate for the inaudible components of sound prior to computation of
tone ratios according to Annex D of the ECMA-74 standards.
22
Idle*
2.6 bels (typ)
2.7 bels (max)
Barracuda SATA Product Manual, Rev. B
www.seagate.com
Seek
2.8 bels (typ)
3.0 bels (max)