Accordion: Toward soft Near-Threshold Voltage Computing

Ulya Karpuzcu, Ismail Akturk, Nam Sung Kim

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

9 Scopus citations

Abstract

While more cores can find place in the unit chip area every technology generation, excessive growth in power density prevents simultaneous utilization of all. Due to the lower operating voltage, Near-Threshold Voltage Computing (NTC) promises to fit more cores in a given power envelope. Yet NTC prospects for energy efficiency disappear without mitigating (i) the performance degradation due to the lower operating frequency; (ii) the intensified vulnerability to parametric variation. To compensate for the first barrier, we need to raise the degree of parallelism - the number of cores engaged in computation. NTC-prompted power savings dominate the power cost of increasing the core count. Hence, limited parallelism in the application domain constitutes the critical barrier to engaging more cores in computation. To avoid the second barrier, the system should tolerate variation-induced errors. Unfortunately, engaging more cores in computation exacerbates vulnerability to variation further. To overcome NTC barriers, we introduce Accordion, a novel, light-weight framework, which exploits weak scaling along with inherent fault tolerance of emerging R(ecognition), M(ining), S(ynthesis) applications. The key observation is that the problem size not only dictates the number of cores engaged in computation, but also the application output quality. Consequently, Accordion designates the problem size as the main knob to trade off the degree of parallelism (i.e. the number of cores engaged in computation), with the degree of vulnerability to variation (i.e. the corruption in application output quality due to variation-induced errors). Parametric variation renders ample reliability differences between the cores. Since RMS applications can tolerate faults emanating from data-intensive program phases as opposed to control, variation-afflicted Accordion hardware executes fault-tolerant data-intensive phases on error-prone cores, and reserves reliable cores for control.

Original languageEnglish (US)
Title of host publication20th IEEE International Symposium on High Performance Computer Architecture, HPCA 2014
PublisherIEEE Computer Society
Pages72-83
Number of pages12
ISBN (Print)9781479930975
DOIs
StatePublished - Jan 1 2014
Event20th IEEE International Symposium on High Performance Computer Architecture, HPCA 2014 - Orlando, FL, United States
Duration: Feb 15 2014Feb 19 2014

Publication series

NameProceedings - International Symposium on High-Performance Computer Architecture
ISSN (Print)1530-0897

Other

Other20th IEEE International Symposium on High Performance Computer Architecture, HPCA 2014
CountryUnited States
CityOrlando, FL
Period2/15/142/19/14

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Karpuzcu, U., Akturk, I., & Kim, N. S. (2014). Accordion: Toward soft Near-Threshold Voltage Computing. In 20th IEEE International Symposium on High Performance Computer Architecture, HPCA 2014 (pp. 72-83). [6835977] (Proceedings - International Symposium on High-Performance Computer Architecture). IEEE Computer Society. https://doi.org/10.1109/HPCA.2014.6835977