Title
iPatch: Intelligent fault patching to improve energy efficiency
Abstract
Dynamic voltage and frequency scaling can provide substantial energy savings but is limited by SRAM since some cells will fail at very low voltages. Due to process variation effects, a small subset of SRAM cells will be more sensitive to voltage reduction, requiring increased margins and limiting energy savings. Since large arrays like caches are most vulnerable to cell failures, recent proposals suggest disabling failing portions of the cache to enable low voltage operation. Although such approaches save power, energy reduction is limited because reducing the effective cache size increases program runtimes. In this paper, we present iPatch, a solution to regain this lost performance and enable energy savings by exploiting the redundancy inherent in superscalar processors. By relying on existing microarchitectural structures and mechanisms to "patch" the faulty parts of caches, we enable further energy reduction with minimal overhead and complexity. Furthermore, because no critical paths or circuits are affected by our implementation, there is no impact on normal-voltage operation. For high cell failure rates, our results show significant energy savings with iPatch as well as an 18% reduction in energy-delay product compared to prior work.
Year
DOI
Venue
2015
10.1109/HPCA.2015.7056052
High Performance Computer Architecture
Keywords
Field
DocType
sram chips,cache storage,power aware computing,sram cells,cache size,cell failure rates,dynamic voltage and frequency scaling,energy efficiency,energy reduction,energy savings,energy-delay product,ipatch,intelligent fault patching,low voltage operation,microarchitectural structures,normal-voltage operation,process variation effects
Voltage reduction,Computer science,Efficient energy use,Cache,CPU cache,Parallel computing,Real-time computing,Static random-access memory,Redundancy (engineering),Frequency scaling,Process variation
Conference
ISSN
Citations 
PageRank 
1530-0897
6
0.46
References 
Authors
19
3
Name
Order
Citations
PageRank
David J. Palframan1683.90
Nam Sung Kim23268225.99
Mikko H. Lipasti331323.29