Seagate Barracuda 7200.7 ST3120022A, Product Manual

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16 Barracuda 7200.7 Product Manual, Rev. D
2.11 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.
Note. 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 l average access time)
*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.
Table 1: Fluid Dynamic Bearing (FDB) motor acoustics
Acoustic mode
Models Idle* Quiet seek Performance seek
ST3160021A
ST3160023A
ST3120022A
ST3120026A
ST380011A
ST380013A <2.5 bels (typ)
2.7 bels (max) 2.8 bels (typ)
3.0 bels (max) 3.4 bels (typ)
3.7 bels (max)
ST340014A <2.2 bels (typ)
2.4 bels (max) 2.5 bels (typ)
2.7 bels (max) 3.1 bels (typ)
3.5 bels (max)