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Author Raghunathan, Anand ♦ Venkatesan, Rangharajan ♦ Venkataramani, Swagath ♦ Ramasubramanian, Shankar Ganesh ♦ Roy, Kaushik
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Abstract General-purpose Graphics Processing Units (GPGPUs) are widely used for executing massively parallel workloads from various application domains. Feeding data to the hundreds to thousands of cores that current GPGPUs integrate places great demands on the memory hierarchy, fueling an ever-increasing demand for on-chip memory. In this work, we propose STAG, a high density, energy-efficient GPGPU cache hierarchy design using a new spintronic memory technology called Domain Wall Memory (DWM). DWMs inherently offer unprecedented benefits in density by storing multiple bits in the domains of a ferromagnetic nanowire, which logically resembles a bit-serial tape. However, this structure also leads to a unique challenge that the bits must be sequentially accessed by performing "shift" operations, resulting in variable and potentially higher access latencies. To address this challenge, STAG utilizes a number of architectural techniques : (i) a hybrid cache organization that employs different DWM bit-cells to realize the different memory arrays within the GPGPU cache hierarchy, (ii) a clustered, bit-interleaved organization, in which the bits in a cache block are spread across a cluster of DWM tapes, allowing parallel access, (iii) tape head management policies that predictively configure DWM arrays to reduce the expected number of shift operations for subsequent accesses, and (iv) a shift aware pro- motion buffer (SaPB), in which accesses to the DWM cache are predicted based on intra-warp locality, and locations that would incur a large shift penalty are promoted to a smaller buffer. Over a wide range of benchmarks from the Rodinia, IS- PASS and Parboil suites, STAG achieves significant benefits in performance (12.1% over SRAM and 5.8% over STT-MRAM) and energy (3.3X over SRAM and 2.6X over STT-MRAM)
Description Affiliation: Purdue University (Venkatesan, Rangharajan; Ramasubramanian, Shankar Ganesh; Venkataramani, Swagath; Roy, Kaushik; Raghunathan, Anand)
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1981-04-01
Publisher Place New York
Journal ACM SIGARCH Computer Architecture News (CARN)
Volume Number 42
Issue Number 3
Page Count 12
Starting Page 253
Ending Page 264


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Source: ACM Digital Library