Adaptive Battery Life Extender (Able-2) Feature; Performance Idle Mode; Active Idle Mode; Low Power Idle Mode - IBM DTCA-23240 - Travelstar 3.2 GB Hard Drive Specifications

10.5 Adaptive Battery Life Extender (ABLE-2) Feature

This feature provides power saving without performance degradation. The ABLE-2 technology intelligently
manages transition among power modes within the device by monitoring access patterns of the host.
This feature has three idle modes; Performance Idle mode, Active Idle mode, and Low Power Idle mode.
This feature allows the host to select a power management level. The power management level is a scale
from the lowest power consumption setting of 01h to the maximum performance level of FEh. Device per-
formance may increase with increasing power management levels. Device power consumption may increase
with increasing power management levels. The 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 FEATURES subcommand to enable Advanced Power Management
A SET FEATURES subcommand to disable Advanced Power Management
The ABLE-2 is independent of the Standby timer setting. If both ABLE-2 and the Standby timer are set,
the device will goto the Standby state when the timer times out or the device's Advanced Power Manage-
ment algorithm indicates that it is time to enter the Standby state.
The IDENTIFY DEVICE response word 83, bit 3 indicates that Advanced Power Management is sup-
ported 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 35-50% 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 40ms.

10.5.3 Low Power Idle mode

Power consumption is 55%-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 algo-
rithm monitors the frequency of commands over intervals of interest, usually several seconds. The algorithm
judges how long the current burst of commands will continue by maintaining a distribution of command
frequencies. After each command, the algorithm calculates the probability that the current burst of com-
mands is complete based on the statistics of the distribution.
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O E M Specifications of DTCA-2xxxx 2.5 inch H D D