Paper Info
Title
AVATAR: A Variable-Retention-Time (VRT) Aware Refresh for DRAM Systems
Abstract
Multirate refresh techniques exploit the non-uniformity in retention times of DRAM cells to reduce the DRAM refresh overheads. Such techniques rely on accurate profiling of retention times of cells, and perform faster refresh only for a few rows which have cells with low retention times. Unfortunately, retention times of some cells can change at runtime due to Variable Retention Time (VRT), which makes it impractical to reliably deploy multirate refresh. Based on experimental data from 24 DRAM chips, we develop architecture-level models for analyzing the impact of VRT. We show that simply relying on ECC DIMMs to correct VRT failures is unusable as it causes a data error once every few months. We propose AVATAR, a VRT-aware multirate refresh scheme that adaptively changes the refresh rate for different rows at runtime based on current VRT failures. AVATAR provides a time to failure in the regime of several tens of years while reducing refresh operations by 62%-72%.
Year
DOI
Venue
2015
10.1109/DSN.2015.58
The International Conference on Dependable Systems and Networks
Keywords
Field
DocType
Dynamic Random Access Memory, Refresh Rate, Variable Retention Time, Error Correcting Codes, Performance, Memory Scrubbing
Dram,Dynamic random-access memory,Memory scrubbing,DIMM,Computer science,Profiling (computer programming),Real-time computing,Refresh rate,Avatar,Embedded system
Conference
ISSN
Citations 
PageRank 
1530-0889
66
1.23
References 
Authors
18
5
Name
Order
Citations
PageRank
Moinuddin K. Qureshi12639110.61
Dae Hyun Kim250546.95
Samira Manabi Khan359618.12
Prashant J. Nair434615.74
Onur Mutlu59446357.40