Seagate Barracuda ST340015A - Manual (Page 24)

16 Barracuda 5400.1 Product Manual, Rev. G
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 latency + 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
Model Idle* Quiet seek Performance seek
ST340015A 2.6 bels (typ)
2.8 bels (max) 2.7 bels (typ)
2.9 bels (max) 2.8 bels (typ)
3.0 bels (max)