Energy Management; Ibm Energyscale Technology - IBM Power 710 Technical Overview And Introduction

2.15 Energy management

The Power 710 and 730 servers are designed with features to help clients become more
energy efficient. The IBM Systems Director Active Energy Manager exploits EnergyScale
technology, enabling advanced energy management features to dramatically and dynamically
conserve power and further improve energy efficiency. Intelligent Energy optimization
capabilities enable the POWER7 processor to operate at a higher frequency for increased
performance and performance per watt or dramatically reduce frequency to save energy.

2.15.1 IBM EnergyScale technology

IBM EnergyScale technology provides functions to help the user understand and dynamically
optimize the processor performance versus processor energy consumption, and system
workload, to control IBM Power Systems power and cooling usage.
On POWER7 processor-based systems, the thermal power management device (TPMD)
card is responsible for collecting the data from all system components, changing operational
parameters in components, and interacting with the IBM Systems Director Active Energy
Manager (an IBM Systems Directors plug-in) for energy management and control.
IBM EnergyScale makes use of power and thermal information collected from the system in
order to implement policies that can lead to better performance or better energy utilization.
IBM EnergyScale features include:
Power trending
EnergyScale provides continuous collection of real-time server energy consumption. This
enables administrators to predict power consumption across their infrastructure and to
react to business and processing needs. For example, administrators can use such
information to predict datacenter energy consumption at various times of the day, week, or
month.
Thermal reporting
IBM Director Active Energy Manager can display measured ambient temperature and
calculated exhaust heat index temperature. This information can help identify data center
hot spots that need attention.
Power Saver Mode
Power Saver Mode lowers the processor frequency and voltage on a fixed amount,
reducing the energy consumption of the system while still delivering predictable
performance. This percentage is predetermined to be within a safe operating limit and is
not user configurable. The server is designed for a fixed frequency drop of up to 30%
down from nominal frequency. (The actual value depends on the server type and
configuration.) Power Saver Mode is not supported during boot or re-boot although it is a
persistent condition that will be sustained after the boot when the system starts executing
instructions.
Dynamic Power Saver Mode
Dynamic Power Saver Mode varies processor frequency and voltage based on the
utilization of the POWER7 processors. Processor frequency and utilization are inversely
proportional for most workloads, implying that as the frequency of a processor increases,
its utilization decreases, given a constant workload. Dynamic Power Saver Mode takes
advantage of this relationship to detect opportunities to save power, based on measured
real-time system utilization.
Chapter 2. Architecture and technical overview
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