Skip to main content

Controlling Disk Acoustic Modes

Most modern HDDs support normal and quiet disk acoustic modes. In "quiet" mode, reduced acceleration and velocity of the disk head result in reduced power consumption. Although disk drive power is reduced in quiet mode, disk performance is reduced, and as a result, input/output operations may run for a longer period (although at reduced power). If only power is of interest (power capping), then HDD quiet mode may be appropriate, provided the performance penalty is acceptable. However, when considering energy consumed (integral of power over workload runtime), depending on the ratio between power reduction and runtime prolongation in quiet mode, energy may be not saved. In fact, it may even be increased relative to normal disk operation mode.

We worked to characterize the types of workloads for which quiet mode may save (or not save) energy. We leveraged the insights gained from this research in the SAMCEE disk mode controller (see SAMCEE presentation and "Leveraging disk drive acoustic modes for power management").