GPU wattch: Enabling energy optimizations in GPGPUs

Jingwen Leng, Tayler Hetherington, Ahmed ElTantawy, Syed Gilani, Nam Sung Kim, Tor M. Aamodt, Vijay Janapa Reddi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

General-purpose GPUs (GPGPUs) are becoming prevalent in mainstream computing, and performance per watt has emerged as a more crucial evaluation metric than peak performance. As such, GPU architects require robust tools that will enable them to quickly explore new ways to optimize GPGPUs for energy efficiency. We propose a new GPGPU power model that is configurable, capable of cycle-level calculations, and carefully validated against real hardware measurements. To achieve configurability, we use a bottom-up methodology and abstract parameters from the microarchitectural components as the model's inputs. We developed a rigorous suite of 80 microbenchmarks that we use to bound any modeling uncertainties and inaccuracies. The power model is comprehensively validated against measurements of two commercially available GPUs, and the measured error is within 9.9% and 13.4% for the two target GPUs (GTX 480 and Quadro FX5600). The model also accurately tracks the power consumption trend over time. We integrated the power model with the cycle-level simulator GPGPU-Sim and demonstrate the energy savings by utilizing dynamic voltage and frequency scaling (DVFS) and clock gating. Traditional DVFS reduces GPU energy consumption by 14.4% by leveraging within-kernel runtime variations. More finer-grained SM cluster-level DVFS improves the energy savings from 6.6% to 13.6% for those benchmarks that show clustered execution behavior. We also show that clock gating inactive lanes during divergence reduces dynamic power by 11.2%.

Original languageEnglish (US)
Title of host publicationISCA 2013 - 40th Annual International Symposium on Computer Architecture, Conference Proceedings
Pages487-498
Number of pages12
DOIs
StatePublished - Aug 12 2013
Externally publishedYes
Event40th Annual International Symposium on Computer Architecture, ISCA 2013 - Tel-Aviv, Israel
Duration: Jun 23 2013Jun 27 2013

Publication series

NameProceedings - International Symposium on Computer Architecture
ISSN (Print)1063-6897

Other

Other40th Annual International Symposium on Computer Architecture, ISCA 2013
CountryIsrael
CityTel-Aviv
Period6/23/136/27/13

Keywords

  • CUDA
  • Energy
  • GPU architecture
  • Power estimation

ASJC Scopus subject areas

  • Hardware and Architecture

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