Specifications
Chapter 2. Architecture and technical overview 117
A new power savings mode, called
inherit host setting, is available and is only applicable
to partitions. When configured to use this setting, a partition will adopt the power savings
mode of its hosting server. By default, all partitions with dedicated processing units, and
the system processor pool, are set to the inherit host setting.
On POWER7 processor-based systems, several EnergyScales are imbedded in
the hardware and do not require an operating system or external management
component. More advanced functionality requires Active Energy Manager (AEM) and
IBM Systems Director.
Table 2-39 provides a list of all features supported, showing all cases in which AEM is not
required. Table 2-39 also details the features that can be activated by traditional user
interfaces (for example, ASMI and HMC).
Table 2-39 AEM support
The Power 770 and Power 780 systems implement all the EnergyScale capabilities listed
in 2.15.1, “IBM EnergyScale technology” on page 114.
2.15.2 Thermal power management device card
The thermal power management device (TPMD) card is a separate micro controller installed
on some POWER6 processor-based systems, and on all POWER7 processor-based
systems. It runs real-time firmware whose sole purpose is to manage system energy.
The TPMD card monitors the processor modules, memory, environmental temperature, and
fan speed. Based on this information, it can act upon the system to maintain optimal power
and energy conditions (for example, increase the fan speed to react to a temperature
change). It also interacts with the IBM Systems Director Active Energy Manager to report
power and thermal information and to receive input from AEM on policies to be set. The
TPMD is part of the EnergyScale infrastructure.
Feature Active Energy Manager (AEM) required ASMI HMC
Power Trending Y N N
Thermal Reporting Y N N
Static Power Saver N Y Y
Dynamic Power Saver Y N N
Power Capping Y N N
Energy-optimized Fans N - -
Processor Core Nap N - -
Processor Core Sleep N - -
Processor Folding N - -
EnergyScale for I/O N - -
Server Power Down Y - -
Partition Power
Management
Y--