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Drive Specifications
2.9
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 3
Fluid Dynamic Bearing (FDB) motor acoustics
Idle*
Seek
All models
2.3 bels (typical)
2.4 bels (max)
2.7 bels (typical)
2.8 bels (max)
*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.
2.9.1
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.
2.10
Electromagnetic immunity
When properly installed in a representative host system, the drive operates without errors or degradation in performance
when subjected to the radio frequency (RF) environments defined in Table 4.
Table 4
Radio frequency environments
Test
Description
Performance
level
Reference
standard
Electrostatic discharge
Contact, HCP, VCP: ± 4 kV; Air: ± 8 kV
B
EN61000-4-2: 95
Radiated RF immunity
80MHz to 1,000MHz, 3 V/m,
80% AM with 1kHz sine
A
EN61000-4-3: 96
Electrical fast transient
± 1 kV on AC mains, ± 0.5 kV on external I/O
B
EN61000-4-4: 95
Surge immunity
± 1 kV differential, ± 2 kV common,
AC mains
B
EN61000-4-5: 95
Conducted RF immunity
150kHz to 80MHz, 3 Vrms, 80% AM with 1kHz sine
A
EN61000-4-6: 97
EN61000-4-11: 94
Voltage dips, interrupts
0% open, 5 seconds
0% short, 5 seconds
40%, 0.10 seconds
70%, 0.01 seconds
C
C
C
B
Seagate SkyHawk Product Manual, Rev. A
16