Recovery-driven design: Exploiting error resilience in design of energy-efficient processors

Sartori, John M.

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https://hdl.handle.net/2142/18286 Copy

Description

Title

Recovery-driven design: Exploiting error resilience in design of energy-efficient processors

Author(s)

Sartori, John M.

Issue Date

2011-01-14T22:44:50Z

Director of Research (if dissertation) or Advisor (if thesis)

Kumar, Rakesh

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• recovery-driven design
• energy efficiency
• error resilience

Abstract

Conventional CAD methodologies optimize a processor module for correct operation and prohibit timing violations during nominal operation. We propose recovery-driven design, a design approach that optimizes a processor module for a target timing error rate instead of correct operation. The target error rate is chosen based on how many errors can be gainfully tolerated by a hardware or software error resilience mechanism. We show that significant power bene ts are possible from a recovery-driven design approach that deliberately allows errors caused by voltage overscaling to occur during nominal operation, while relying on an error resilience technique to tolerate these errors. We present a detailed evaluation and analysis of such a design-level methodology that minimizes the power of a processor module for a target error rate. We show how this design-level methodology can be extended to design recovery-driven processors -- processors that are optimized to take advantage of hardware or software error resilience. These may be single-core processors or heterogeneously-reliable multi-core processors, in which individual cores are optimized for different reliability targets. We also discuss a gradual slack recovery-driven design approach that optimizes for a range of error rates to create soft processors -- processors that have graceful failure characteristics and the ability to trade throughput or output quality for additional energy savings over a range of error rates. We demonstrate significant power benefits over conventional design -- 11.8% on average over all modules and error rate targets, and up to 29.1% for individual modules. Processor- level benefits are 19.0%, on average. Benefits increase when recovery-driven design is coupled with an error resilience mechanism or when the number of available voltage domains increases.

Graduation Semester

2010-12

Permalink

http://hdl.handle.net/2142/18286

Copyright and License Information

Copyright 2010 John M. Sartori

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