Advanced Power Management Feature Set (Apm) - Hitachi 7K400 - Deskstar Hard Drive Specifications

10.14 Advanced Power Management feature set (APM)

This feature allows the host to select an advanced power management level. The advanced power management level
is a scale from the lowest power consumption setting of 01h to the maximum performance level of FEh. Device
performance may increase with increasing advanced power management levels. Device power consumption may
increase with increasing advanced power management levels. The advanced power management levels contain
discrete bands described in the section of SET FEATURES command in detail. This feature set uses the following
functions:
• A SET FEATURES subcommand to enable Advanced Power Management
• A SET FEATURES subcommand to disable Advanced Power Management
Advanced Power Management is independent of the Standby timer setting. If both Advanced Power Management and the
Standby timer are set, the device will go to the Standby state when the timer times out or the device's Advanced Power Man-
agement algorithm indicates that the Standby state should be entered.
The IDENTIFY DEVICE response word 83, bit 3 indicates that Advanced Power Management feature is supported
if set. Word 86, bit 3 indicates that Advanced Power Management is enabled if set. Word 91, bits 7-0 contains the
current Advanced Power Management level if it is enabled.
Deskstar 7K400 Hard Disk Drive Specification
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