85,373 research outputs found
Enabling Fine-Grain Restricted Coset Coding Through Word-Level Compression for PCM
Phase change memory (PCM) has recently emerged as a promising technology to
meet the fast growing demand for large capacity memory in computer systems,
replacing DRAM that is impeded by physical limitations. Multi-level cell (MLC)
PCM offers high density with low per-byte fabrication cost. However, despite
many advantages, such as scalability and low leakage, the energy for
programming intermediate states is considerably larger than programing
single-level cell PCM. In this paper, we study encoding techniques to reduce
write energy for MLC PCM when the encoding granularity is lowered below the
typical cache line size. We observe that encoding data blocks at small
granularity to reduce write energy actually increases the write energy because
of the auxiliary encoding bits. We mitigate this adverse effect by 1) designing
suitable codeword mappings that use fewer auxiliary bits and 2) proposing a new
Word-Level Compression (WLC) which compresses more than 91% of the memory lines
and provides enough room to store the auxiliary data using a novel restricted
coset encoding applied at small data block granularities.
Experimental results show that the proposed encoding at 16-bit data
granularity reduces the write energy by 39%, on average, versus the leading
encoding approach for write energy reduction. Furthermore, it improves
endurance by 20% and is more reliable than the leading approach. Hardware
synthesis evaluation shows that the proposed encoding can be implemented
on-chip with only a nominal area overhead.Comment: 12 page
Energy Saving Techniques for Phase Change Memory (PCM)
In recent years, the energy consumption of computing systems has increased
and a large fraction of this energy is consumed in main memory. Towards this,
researchers have proposed use of non-volatile memory, such as phase change
memory (PCM), which has low read latency and power; and nearly zero leakage
power. However, the write latency and power of PCM are very high and this,
along with limited write endurance of PCM present significant challenges in
enabling wide-spread adoption of PCM. To address this, several
architecture-level techniques have been proposed. In this report, we review
several techniques to manage power consumption of PCM. We also classify these
techniques based on their characteristics to provide insights into them. The
aim of this work is encourage researchers to propose even better techniques for
improving energy efficiency of PCM based main memory.Comment: Survey, phase change RAM (PCRAM
From FPGA to ASIC: A RISC-V processor experience
This work document a correct design flow using these tools in the Lagarto RISC- V Processor and the RTL design considerations that must be taken into account, to move from a design for FPGA to design for ASIC
Exploring Application Performance on Emerging Hybrid-Memory Supercomputers
Next-generation supercomputers will feature more hierarchical and
heterogeneous memory systems with different memory technologies working
side-by-side. A critical question is whether at large scale existing HPC
applications and emerging data-analytics workloads will have performance
improvement or degradation on these systems. We propose a systematic and fair
methodology to identify the trend of application performance on emerging
hybrid-memory systems. We model the memory system of next-generation
supercomputers as a combination of "fast" and "slow" memories. We then analyze
performance and dynamic execution characteristics of a variety of workloads,
from traditional scientific applications to emerging data analytics to compare
traditional and hybrid-memory systems. Our results show that data analytics
applications can clearly benefit from the new system design, especially at
large scale. Moreover, hybrid-memory systems do not penalize traditional
scientific applications, which may also show performance improvement.Comment: 18th International Conference on High Performance Computing and
Communications, IEEE, 201
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