IBM Power 595, Технический обзор и введение

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Chapter 2. Architectural and technical overview
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EnergyScale is an infrastructure that enables:
Real-time measurements feedback to address variability and unpredictability of
parameters such as power, temperature, activity, and performance
Mechanisms for regulating system activity, component operating levels, and environmental
controls such as processor, memory system, fan control and disk power, and a dedicated
control structure with mechanisms for interactions with OS, hypervisor, and applications.
Interaction and integration that provides:
– Policy-guided power management to support user-directed policies and operation
modes
– Critical event and comprehensive usage information
– Support integration into larger scope system management frameworks
Design principles
The EnergyScale architecture is based on design principles that are used not only in
POWER6 processor-based servers but also in the IBM BladeCenter® and IBM System x™
product lines. These principles are the result of fundamental research on system-level power
management performed by the IBM Research Division, primarily in the Austin Research
Laboratory. The major design principles are as follows:
Implementation is primarily an out-of-band power management scheme. EnergyScale
utilizes one or more dedicated adapters (thermal power management devices (TPMD)) or
one or more service processors to execute the management logic. EnergyScale
communicates primarily with both in-system (service processor) and off-system (for
example, Active Energy Manager) entities.
Implementation is measurement-based, that is it continuously takes measurements of
voltage and current to calculate the amount of power drawn. It uses temperature sensors
to measure heat, and uses performance counters to determine the characteristics of
workloads. EnergyScale directly measures voltage, current, and temperature to determine
the characteristics of workloads (for example sensors and critical path monitors).
Implementation uses real-time measurement and control. When running out-of-band, the
EnergyScale implementation relies on real-time measurement and control to ensure that
the system meets the specified power and temperature goals. Timings are honored down
to the single-millisecond range.
System-level Power Management™ is used. EnergyScale considers a holistic view of
power consumption. Most other solutions focus largely or exclusively on the system
processor.
Multiple methods are available to control power and thermal characteristics of a system, it
allows sensing and allows for acting on system parameters to achieve control. The
EnergyScale implementation uses multiple actuators to alter the power consumption and
heat dissipation of the processors and the memory in the system.
The architecture contains features that ensure safe, continued operation of the system
during adverse power or thermal conditions, and in certain cases in which the
EnergyScale implementation itself fails.
The user has indirect control over Power Management behavior by using configurable
policies, similar to existing offerings from other product offerings (Active Energy Manager).
Figure 2-24 on page 66 show the POWER6 power management architecture.