On Chip Controller; Energy Consumption Estimation - IBM Power Systems S822LC Technical Overview And Introduction

EnergyScale for I/O
POWER8 processor-based systems automatically power off hot-pluggable PCI adapter
slots that are empty or not being used. System firmware automatically scans all pluggable
PCI slots at regular intervals, looking for those slots that meet the criteria for being not in
use and powering them off. This support is available for all POWER8 processor-based
servers and the expansion units that they support.
Dynamic power saver mode
On POWER8 processor-based systems, several EnergyScale technologies are
embedded in the hardware and do not require an operating system or external
management component. Fan control, environmental monitoring, and system energy
management are controlled by the On Chip Controller (OCC) and associated components.

On Chip Controller

POWER8 invested in power management innovations. A new OCC that uses an embedded
IBM PowerPC® core with 512 KB of SRAM runs real-time control firmware to respond to
workload variations by adjusting the per-core frequency and voltage based on activity,
thermal, voltage, and current sensors.
The OCC also enables more granularity in controlling the energy parameters in the processor,
and increases reliability in energy management by having one controller in each processor
that can perform certain functions independently of the others.
POWER8 also includes an internal voltage regulation capability that enables each core to run
at a different voltage. Optimizing both voltage and frequency for workload variation enables a
better increase in power savings versus optimizing frequency only.

Energy consumption estimation

Often, for Power Systems servers, various energy-related values are important:
Maximum power consumption and power source loading values
These values are important for site planning and are described in the POWER8
processor-based systems information IBM Knowledge Center at the following website:
http://www.ibm.com/support/knowledgecenter/api/redirect/powersys/v3r1m5/index.jsp
Search for type and model number and "server specifications". For example, for the Power
S822LC servers, search for "8335-GCB" .
An estimation of the energy consumption for a certain configuration
Calculate the energy consumption for a certain configuration in the IBM Systems Energy
Estimator at the following website:
http://www-912.ibm.com/see/EnergyEstimator
In that tool, select the type and model for the system, and enter details about the
configuration and CPU usage that you want. As a result, the tool shows the estimated
energy consumption and the waste heat at the usage that you want and also at full usage.
Appendix A. Server racks and energy management
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