Copyright by William Lloyd Bircher 2010 - The Laboratory for ...

Chapter 2 Methodology
The development of power models based on performance events requires the
measurement of power and performance on systems running a wide range of workloads.
This chapter describes the methodology for measuring power and performance events on
actual systems (not simulation) running realistic workloads. The first section describes
techniques and equipment for in-system measurement of power across a range of systems
and components. The compositions of three systems are defined: server, desktop and
laptop. The second section shows how system parameters such as temperature, voltage
and frequency can be manipulated to expose and quantify underlying properties of
systems. The third section describes how performance monitoring counters (PMC) can
be tracked in a manner that has minimal impact on the observed system. The last section
describes which workloads are preferred for power management analysis and why.
2.1 Measuring System and Component Power
To measure power consumption, a range of instrumentation methodologies are used.
Each methodology is designed to match measurement requirements while conforming to
the constraints of the measured system. The systems and measurement requirements are:
1) aggregate CPU power in a desktop system, 2) subsystem-level power in a server
system, 3) subsystem-level power in a mobile system.
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