Power-Management Modes - Seagate ST920210AS Product Manual

2.8.4

Power-management modes

The drive provides programmable power management to provide greater energy efficiency. In most systems,
you can control power management through the system setup program. The drive features the following
power-management modes:
Table 4: Power management modes
Power modes
Active (operating)
Idle
Idle, active
Idle, low power
Standby
Sleep
• Active mode
The drive is in Active mode during the read/write and seek operations.
• Idle mode
The buffer remains enabled in performance mode, and the drive accepts all commands and returns to Active
mode any time disc access is necessary.
• Standby mode
The drive enters Standby mode when the host sends a Standby Immediate command. If the host has set the
standby timer, the drive can also enter Standby mode automatically after the drive has been inactive for a
specifiable length of time. The standby timer delay is established using a Standby or Idle command. In Standby
mode, the drive buffer is enabled, the heads are parked and the spindle is at rest. The drive accepts all
commands and returns to Active mode any time disc access is necessary.
• Sleep mode
The drive enters Sleep mode after receiving a Sleep command from the host. In Sleep mode, the drive buffer
is disabled, the heads are parked and the spindle is at rest. The drive leaves Sleep mode after it receives a
Hard Reset or Soft Reset from the host. After receiving a reset, the drive exits Sleep mode and enters Standby
mode with all current translation parameters intact.
LD25 Series 5400.2 Product Manual, Rev. C
Heads Spindle
Tracking Rotating
Tracking Rotating
Floating Rotating
Parked Rotating
Parked Stopped
Parked Stopped
Buffer
Enabled
Enabled
Disabled
Disabled
Enabled
Disabled
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