Seagate ST930818SM データシート
18
EE25.2 Series Product Manual, Rev. E
2.9.4
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:
you can control power management through the system setup program. The drive features the following
power-management modes:
• Active mode
The drive is in Active mode during the read/write and seek operations.
• Idle mode
The buffer remains enabled, and the drive accepts all commands and returns to Active mode any time disc
access is necessary.
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.
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.
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.
• Idle and Standby timers
Each time the drive performs an Active function (read, write or seek), the standby timer is reinitialized and
begins counting down from its specified delay times to zero. If the standby timer reaches zero before any drive
activity is required, the drive makes a transition to Standby mode. In both Idle and Standby mode, the drive
accepts all commands and returns to Active mode when disc access is necessary.
begins counting down from its specified delay times to zero. If the standby timer reaches zero before any drive
activity is required, the drive makes a transition to Standby mode. In both Idle and Standby mode, the drive
accepts all commands and returns to Active mode when disc access is necessary.
Power modes
Heads
Spindle
Buffer
Std timing
Active (operating)
Tracking
Rotating
Enabled
Idle, performance
Tracking
Rotating
Enabled
Idle, active
Floating
Rotating
Disabled
100ms
Idle, low power
Parked
Rotating
Disabled
5.00 secs
Standby
Parked
Stopped
Disabled
Set by host
Sleep
Parked
Stopped
Disabled
Set by host