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16 Barracuda Serial ATA V Product Manual, Rev. B
2.10.6 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.
2.10.6.1 Operating vibration
The maximum vibration levels that the drive may experience while meeting
the performance standards specified in this document are specified below.
2.10.6.2 Nonoperating vibration
The maximum nonoperating vibration levels that the drive may experience
without incurring physical damage or degradation in performance when sub-
sequently put into operation are specified below.
2.11 Drive 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:
(Number of seeks per second = 0.4 / (average latency + average access time)
5–22 Hz 0.25-inch displacement (zero to peak)
22–350 Hz 0.5 Gs acceleration (zero to peak)
5–22 Hz 1.0-inch displacement (zero to peak)
22–350 Hz 5.0 Gs acceleration (zero to peak)
Table 4: Fluid Dynamic Bearing (FDB) motor acoustics
Acoustic mode
Models Idle* Quiet seek Performance seek
ST3120023AS
ST380023AS
2.8 bels (typ)
3.0 bels (max)
2.8 bels (typ)
3.0 bels (max)
3.3 bels (typ)
3.6 bels (max)
ST360015AS 2.1 bels (typ)
<2.5 bels (max)
2.4 bels (typ)
2.8 bels (max)
3.0 bels (typ)
3.4 bels (max)