COP: To compress and protect main memory

David J. Palframan, Nam Sung Kim, Mikko H. Lipasti

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


Protecting main memories from soft errors typically requires special dual-inline memory modules (DIMMs) which incorporate at least one extra chip per rank to store error-correcting codes (ECC). This increases the cost of the DIMM as well as its power consumption. To avoid these costs, some proposals have suggested protecting non-ECC DIMMs by allocating a portion of memory space to store ECC metadata. However, such proposals can significantly shrink the available memory space while degrading performance due to extra memory accesses. In this work, we propose a technique called COP which uses block-level compression to make room for ECC check bits in DRAM. Because a compressed block with check bits is the same size as an uncompressed block, no extra memory accesses are required and the memory space is not reduced. Unlike other approaches that require explicit compression-tracking metadata, COP employs a novel mechanism that relies on ECC to detect compressed data. Our results show that COP can reduce the DRAM soft error rate by 93% with no storage overhead and negligible impact on performance. We also propose a technique using COP to protect both compressible and incompressible data with minimal storage and performance overheads.

Original languageEnglish (US)
Title of host publicationISCA 2015 - 42nd Annual International Symposium on Computer Architecture, Conference Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages12
ISBN (Electronic)9781450334020
StatePublished - Jun 13 2015
Externally publishedYes
Event42nd Annual International Symposium on Computer Architecture, ISCA 2015 - Portland, United States
Duration: Jun 13 2015Jun 17 2015

Publication series

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


Other42nd Annual International Symposium on Computer Architecture, ISCA 2015
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Hardware and Architecture


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