HyVE: Hybrid Vertex-Edge Memory Hierarchy for Energy-Efficient Graph Processing.

High energy consumption of conventional memory modules (e.g., DRAMs) hinders the further improvement of large-scale graph processing's energy efficiency. The emerging resistive random-access memory (ReRAM) has shown great potential in providing an energy-efficient memory module. However, the performance of ReRAMs suffers from data access patterns with poor locality and large amounts of written data, which are common in graph processing. In this paper, we propose HyVE, a Hybrid Vertex-Edge memory hierarchy for energy-efficient graph processing. In HyVE, we avoid random access and data written to ReRAM modules. HyVE can reduce memory energy consumption by 86.17 percent compared with conventional memory systems. We have also proposed data sharing and bank-level power-gating schemes, which improve the energy efficiency by 1.60x and 1.53x. By analyzing the graph processing model on ReRAMs, we show that ReRAMs are good for read-intensive operations in graph processing (e.g., reading edges), while ReRAM crossbars are not suitable for processing edges because of heavy writing overheads. Our evaluations show that the optimized design achieves two orders of magnitude and 5.90x energy efficiency improvement compared with the CPU-based and conventional memory hierarchy based designs, respectively. Moreover, HyVE achieves 2.83x energy reduction compared with the previous ReRAM-based graph processing architecture. [ABSTRACT FROM AUTHOR]