White Paper - Power Management in Intel Architecture Servers

In the second scenario a user can use a utility which displays the
operating frequencies of the processors. The user can see the
transition of the CPU to the P0 state, which will be more than the
marked frequency of the processor, and can verify that all active cores
are in turbo mode. In the above example, the user will see a frequency
between 2.67–2.8 GHz when turbo mode is engaged, whereas with turbo
mode disabled the maximum operating frequency will be 2.67 GHz.
Thus, turbo mode is not available all the time. The CPU switches to
turbo mode based on the temperature, current, and power limits of
the processor. Typically this mode benefits scalar applications that
are single threaded and thus their performance is directly impacted
by a core’s operating frequency. Whenever some of the cores will be
inactive, the remaining cores that are being used will run at a higher
frequency showing higher performance for the scalar applications.
Intel® Intelligent Power Node Manager
Introduction to Node Manager
The Intel®Intelligent Power Node Manager is a system-level
technology that reports and manages power consumption of all
components in a server. While previously explained technologies
optimize power consumption at a component level, NM manages
power at the platform level to ensure that system-level power
and thermal policies are implemented in a holistic manner.
How Node Manager Works
Figure 5 shows the NM architecture. The NM components can be
implemented in many alternative ways. In Intel-developed server
boards the components are implemented as part of the Manageability
Engine (ME) of the Intel® 5500 series chipset, and communicates with the
external management software via the Base-board Management
Controller (BMC).
Intel® Intelligent Power Node Manager Architecture
Temp
Monitor
Temp
Current
Voltage
PS Temp
New P, T
States
Workload
Info
Disc. P, T
States
TBD
Target
Temp
Fan Speed,
Current Target Temp
Power Supply
Monitor
Thermal
Control
Memory Power
Control
Other Knobs
IB
Workload I/F
AFSC I/F
Fan
Memory Power Control I/F
Defined in NM 1.0
Mem Ctrl DIMM
Monitoring Controlling
NM Policy Engine
Policy Directive
NM
Components
Comm. Layer
Platform H/W
Components
(Evaluates power policies & state, and controls power knobs to achieve power limit goals)
Policies
Temp
Monitor
Power Supply
PMBus I/F
Workload
Monitor
ACPI P/T State
Control I/F
Processor
Processor
Power Control
Figure 5. Node Manager architecture and its interactions with system components�
7
White Paper: Power Management in Intel® Architecture Servers