Acoustic levels
It is possible to view or modify the acoustic settings of an IDE/Serial ATA hard disk if this feature is supported by the disk. Higher acoustic levels will enable faster (but louder) operation. Setting a lower level will make the disk slower and more silent (the read/write head positioning will be slower and more silent). The acoustic setting has no effect on the drive rotation speed.
If supported by the disk, it is possible to modify the acoustic level in this window. By using the slider, the user can choose which is important for him (silent or fast operation or he can select a balance between the endpoints). The recommended acoustic level (determined by the manufacturer) is displayed. Setting any acoustic level will not affect the health of the hard disk.
If two or more hard disks are tested and compared (for example, in a benchmark) all disks should have the same acoustic level configured (eg. fastest or slowest) to get accurate results.
Note: the acoustic level configuration highly depends on the capabilities of the host (controller, motherboad) and the installed drivers. If the controller or the driver does not support this feature, an error message is displayed and the acoustic level remains unchanged. Hopefully more and more manufacturers will build this feature into the controllers and drivers.