O2C: Occasional two-cycle operations for dynamic thermal management in high performance in-order microprocessors

Swaroop Ghosh, Jung Hwan Choi, Patrick Ndai, Kaushik Roy

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

8 Scopus citations

Abstract

In this paper, we propose O2C, a novel non-speculative adaptive thermal management technique that reduces the temperature during die-overheating using supply voltage scaling, while maintaining the rated clock frequency. This is accomplished by (a) scaling down the supply voltage, (b) isolating and predicting the set of critical paths, (c) ensuring (by design) that they are activated rarely, and (d) getting around occasional delay failures (at reduced voltage during dieoverheating) in these paths by two-cycle operations (assuming all standard operations are single-cycle). Two-cycle operation is achieved by stalling the pipeline for extra clock cycles whenever the set of critical paths are activated. The rare two-cycle operation results in a small decrease in IPC (instructions per cycle). Since O2C maintains the rated clock frequency and does not require pipeline stalling during supply voltage ramp-up/ramp-down, it achieves high throughput in a thermally constrained environment. We applied O2C to the integer execution units of an in-order superscalar pipeline. Standard full-chip Dynamic Voltage-Frequency Scaling (DVFS) is very effective in bringing down the temperature, however; it is associated with large throughput loss due to pipeline stalling and slow operating frequency during thermal management. We integrated "O 2C with standard DVFS" (called O2Cα) to demonstrate that it can act as a "first step" before full-scale thermal management is required. Our simulations indeed reveal that O 2Cα policy can avoid the requirement of full-scale DVFS during execution of programs.

Original languageEnglish (US)
Title of host publicationISLPED'08
Subtitle of host publicationProceedings of the 2008 International Symposium on Low Power Electronics and Design
Pages189-192
Number of pages4
DOIs
Publication statusPublished - Dec 17 2008
EventISLPED'08: 13th ACM/IEEE International Symposium on Low Power Electronics and Design - Bangalore, India
Duration: Aug 11 2008Aug 13 2008

Publication series

NameProceedings of the International Symposium on Low Power Electronics and Design
ISSN (Print)1533-4678

Other

OtherISLPED'08: 13th ACM/IEEE International Symposium on Low Power Electronics and Design
CountryIndia
CityBangalore
Period8/11/088/13/08

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All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

Ghosh, S., Choi, J. H., Ndai, P., & Roy, K. (2008). O2C: Occasional two-cycle operations for dynamic thermal management in high performance in-order microprocessors. In ISLPED'08: Proceedings of the 2008 International Symposium on Low Power Electronics and Design (pp. 189-192). (Proceedings of the International Symposium on Low Power Electronics and Design). https://doi.org/10.1145/1393921.1393971