IBM DBCA-204860 - Travelstar 4.8 GB Hard Drive, Specifications

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10.5 Advanced Power Management Feature (ABLE-3)
This feature provides power saving without performance degradation. The Adaptive Battery Life Extender 3
(ABLE-3) technology intelligently manages transition among power modes within the device by monitoring
access patterns of the host.
This technology has three idle modes; Performance Idle mode, Active Idle mode, and Low Power Idle mode.
This feature allows the host to select an advanced power management level. The advanced power manage-
ment 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 Feature command in detail.
This feature set uses the following functions:
A SET F E A T U R E S subcommand to enable Advanced Power Management
A SET F E A T U R E S subcommand to disable Advanced Power Management
The Advanced Power Management feature is independent of the Standby timer setting. If both Advanced
Power Management level and the Standby timer are set, the device will goto the Standby state when the
timer times out or the device's Advanced Power Management algorithm indicates that it is time to enter the
Standby state.
The I D E N T I F Y 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 96,
bits 7-0 contain the current Advanced Power Management level if Advanced Power Management is enabled.
10.5.1 Performance Idle mode
This mode is usually entered immediately after Active mode command processing is complete, instead of
conventional idle mode. In Performance Idle mode, all electronic components remain powered and full fre-
quency servo remains operational. This provides instantaneous response to the next command. The dura-
tion of this mode is intelligently managed as described below.
10.5.2 Active Idle mode
In this mode, power consumption is 45-55% less than that of Performance Idle mode. Additional elec-
tronics are powered off, and the head is parked near the mid-diameter of the disk without servoing.
Recovery time to Active mode is about 20ms.
10.5.3 Low Power Idle mode
Power consumption is 60%-65% less than that of Performance Idle mode. The heads are unloaded on the
ramp, however the spindle is still rotated at the full speed. Recovery time to Active mode is about 300ms.
10.5.4 Transition Time
The transition time is dynamically managed by users recent access pattern, instead of fixed times. The
ABLE-3 algorithm monitors the interval between commands instead of the command frequency of ABLE-2.
The algorithm supposes that next command will come with the same command interval distribution as the
previous access pattern. The algorithm calculates the expected average saving energy and response delay for
next command in several transition time case based on this assumption. And it selects the most effective
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O E M Specifications of DBCA-2xxxxx 2.5 inch H D D