A Proposal to Introduce Power and Energy Notions in Computer

Architecture LaboratoriesAlicia Asín, Darío Suárez, Víctor Viñals

gaZ – DIIS – I3AUniversidad de Zaragoza

HiPEAC Network of Excellence

Power : Major Issue in Computer Architecture

W /

cm

2

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i386i486

Pentium

Pentium Pro

Pentium II

Pentium III

Pentium 4

Nuclear reactor

Technology from older to newer (μm)

Core DUO

Adapted from Pollack (MICRO’99)

How to Introduce Energy and Power in Computer Architecture courses

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Students will get insights in energy and power

Hardware-based

laboratories

Hardware-based

laboratories

Challenging experimentsChallenging experiments

Summary Motivation Goals and requirements Platform description Energy breakdown in an Intel Pentium 4 Conclusions

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Goals Do not alter Computer Architecture course

syllabus Platform for both education and research Obtain the static consumption in a standard

processor

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Requirements Low-cost, reuse resources from the

department Use real hardware Sort platform time training

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Summary Motivation Goals and requirements Platform description Energy breakdown in an Intel Pentium 4 Conclusions

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Platform view

PC under test

PC under test Monitoring

PCMonitoring

PC

Liquid refrigeration

system

Liquid refrigeration

system

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Clamp meterClamp meter

Platform Schematic

Measurements without hacking the motherboard

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Platform Description

PC under testPC under test Intel Pentium 4 GNU/Linux Performance Application

Programming Interface, PAPI, (Dongarra et. al., 2001)

Bare system

Monitoring PCMonitoring PC In-house tool Labview

Widely used, compatible with a lot of data acquisition cards

Sort time of application development

Final application very easy to use

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Frequencyscaling

Application screenshot

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live measurements + store acquired data

Summary Motivation Goals and requirements Platform description Energy breakdown in an Intel Pentium 4 Conclusions

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Intel Pentium 4 Energy Breakdown Static consumption has emerged as a mayor

issue in power-aware architectures Information not available in datasheets

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Dynamic and Static power

Dynamic Static

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Decomposition of the consumption (Sinha et. al., 2003)

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Assertion verification Ensure CPI does not vary

Benchmark choice, LU factorization• Small footprint, low cache miss rate

Hardware counters Keep temperature under control

Liquid refrigeration system

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Measured Results

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Model fits well with the data

Pentium 4 in 130 nm, Vdd = 1.6 VStatic power estimation:

35.94 WLeakage current estimation:

22.46 A

Energy and Average Power

Total energy Average Power

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Dynamic energy remains constant Static power remains constant

Summary Motivation Goals and requirements Platform description Energy breakdown in an Intel Pentium 4 Conclusions

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Conclusions and future work Low-cost platform able to measure and store

the processor consumption Platform enables to carry out interesting

laboratories, valid also for research. E.g., dynamic and static energy decomposition

Aimed to introduce the laboratory in main computer architecture courses taught at the University of Zaragoza

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A Proposal to Introduce Power and Energy Notions in Computer

Architecture LaboratoriesAlicia Asín, Darío Suárez, Víctor Viñals

a.asin@libelium.com, {dario, victor}@unizar.eshttp://webdiis.unizar.es/~gaz/