Drive Acoustics - Seagate ST38421A - U4 8.4 GB Hard Drive Product Manual

U4 Family Product Manual, Rev. D
1.8.6.1 Operating vibration
The following table lists the maximum vibration levels that the drive may expe-
rience while meeting the performance standards specified in this document.
5–21 Hz 0.02-inch displacement (peak to peak)
22–350 Hz 0.5 Gs acceleration (zero to peak)
351–500 Hz 0.3 Gs acceleration (zero to peak)
1.8.6.2 Nonoperating vibration
The following table lists the maximum nonoperating vibration that the
drive may experience without incurring physical damage or degradation
in performance when subsequently put into operation.
5–21Hz 0.02-inch displacement (peak to peak)
22–350 Hz 5.0 Gs acceleration (zero to peak)
351–500 Hz 2.0 Gs acceleration (zero to peak)

1.9 Drive acoustics

Drive acoustics are measured as overall A-weighted acoustic sound
power levels (no pure tones). All measurements are generally consistent
with ISO document 7779. Sound power measurements were taken
under essentially free-field conditions over a reflecting plane. For all
tests, the drive was oriented with the cover facing upward.
Note. For seek mode tests, the drive was 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)
Acoustic mode
Sound power (bels)
Idle mode
3.3 (typ) 3.7 (max)
13
Seek mode
3.9 (typ) 4.3 (max)