A Proposal to Introduce Power and Energy Notions

A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories Alicia Asín, Darío Suárez, Víctor Viñals ga. Z – DIIS – I 3 A Universidad de Zaragoza Hi. PEAC Network of Excellence

Power : Major Issue in Computer Architecture W / cm 2 Nuclear reactor Pentium II Pentium i 386 i 486 Pentium 4 Pentium III Pentium Pro Technology from older to newer (μm) 3/18/2018 Core DUO Adapted from Pollack (MICRO’ 99) A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 2

How to Introduce Energy and Power in Computer Architecture courses Hardwarebased laboratories Challenging experiments q Students will get insights in energy and power 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 3

Summary q Motivation q Goals and requirements q Platform description q Energy breakdown in an Intel Pentium 4 q Conclusions 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 4

Goals q Do not alter Computer Architecture course syllabus q Platform for both education and research q Obtain the static consumption in a standard processor 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 5

Requirements q Low-cost, reuse resources from the department q Use real hardware q Sort platform time training 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 6

Summary q Motivation q Goals and requirements q Platform description q Energy breakdown in an Intel Pentium 4 q Conclusions 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 7

Platform view PC under test Liquid refrigeration system Monitoring PC Clamp meter 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 8

Platform Schematic q Measurements without hacking the motherboard 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 9

Platform Description PC under test q q Intel Pentium 4 Frequency scaling GNU/Linux Performance Application Programming Interface, PAPI, (Dongarra et. al. , 2001) Bare system 3/18/2018 Monitoring PC q q In-house tool Labview Ø Ø Ø Widely used, compatible with a lot of data acquisition cards Sort time of application development Final application very easy to use A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 10

Application screenshot q live measurements + store acquired data 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 11

Summary q Motivation q Goals and requirements q Platform description q Energy breakdown in an Intel Pentium 4 q Conclusions 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 12

Intel Pentium 4 Energy Breakdown q Static consumption has emerged as a mayor issue in power-aware architectures q Information not available in datasheets 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 13

Dynamic and Static power Dynamic 3/18/2018 Static A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 14

Decomposition of the consumption (Sinha et. al. , 2003) 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 15

Assertion verification q Ensure CPI does not vary Ø Benchmark choice, LU factorization • Small footprint, low cache miss rate Ø Hardware counters q Keep temperature under control Ø Liquid refrigeration system 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 16

Measured Results Pentium 4 in 130 nm, Vdd = 1. 6 V Static power estimation: 35. 94 W Leakage current estimation: 22. 46 A q Model fits well with the data 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 17

Energy and Average Power Total energy Dynamic energy remains constant 3/18/2018 Average Power Static power remains constant A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 18

Summary q Motivation q Goals and requirements q Platform description q Energy breakdown in an Intel Pentium 4 q Conclusions 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 19

Conclusions and future work q Low-cost platform able to measure and store the processor consumption q Platform enables to carry out interesting laboratories, valid also for research. E. g. , dynamic and static energy decomposition q Aimed to introduce the laboratory in main computer architecture courses taught at the University of Zaragoza 3/18/2018 A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories WCAE'07 20

A Proposal to Introduce Power and Energy Notions in Computer Architecture Laboratories Alicia Asín, Darío Suárez, Víctor Viñals a. asin@libelium. com, {dario, victor}@unizar. es http: //webdiis. unizar. es/~gaz/