{"title":"Respin: Rethinking Near-Threshold Multiprocessor Design with Non-volatile Memory","authors":"Xiang Pan, Anys Bacha, R. Teodorescu","doi":"10.1109/IPDPS.2017.109","DOIUrl":null,"url":null,"abstract":"Near-threshold computing is emerging as a promising energy-efficient alternative for power-constrained environments. Unfortunately, aggressive reduction in supply voltage to the near-threshold range, albeit effective, faces a host of challenges. This includes higher relative leakage power and high error rates, particularly in dense SRAM structures such as on-chip caches. This paper presents an architecture that rethinks the cache hierarchy in near-threshold multiprocessors. Our design uses STT-RAM to implement all on-chip caches. STT-RAM has several advantages over SRAM at low voltages including low leakage, high density, and reliability. The design consolidates the private caches of near-threshold cores into shared L1 instruction/data caches organized in clusters. We find that our consolidated cache design can service more than 95% of incoming requests within a single cycle. We demonstrate that eliminating the coherence traffic associated with private caches results in a performance boost of 11%. In addition, we propose a hardware-based core management system that dynamically consolidates virtual cores into variable numbers of physical cores to increase resource efficiency. We demonstrate that this approach can save up to 33% in energy.","PeriodicalId":209524,"journal":{"name":"2017 IEEE International Parallel and Distributed Processing Symposium (IPDPS)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2017 IEEE International Parallel and Distributed Processing Symposium (IPDPS)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/IPDPS.2017.109","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
Near-threshold computing is emerging as a promising energy-efficient alternative for power-constrained environments. Unfortunately, aggressive reduction in supply voltage to the near-threshold range, albeit effective, faces a host of challenges. This includes higher relative leakage power and high error rates, particularly in dense SRAM structures such as on-chip caches. This paper presents an architecture that rethinks the cache hierarchy in near-threshold multiprocessors. Our design uses STT-RAM to implement all on-chip caches. STT-RAM has several advantages over SRAM at low voltages including low leakage, high density, and reliability. The design consolidates the private caches of near-threshold cores into shared L1 instruction/data caches organized in clusters. We find that our consolidated cache design can service more than 95% of incoming requests within a single cycle. We demonstrate that eliminating the coherence traffic associated with private caches results in a performance boost of 11%. In addition, we propose a hardware-based core management system that dynamically consolidates virtual cores into variable numbers of physical cores to increase resource efficiency. We demonstrate that this approach can save up to 33% in energy.