DPHSim: A Flexible Simulator for DRAM/PCM-Based Hybrid Memory

In this paper, we demonstrate a flexible simulator for DRAM and PCM based hybrid memory systems. PCM (Phase Change Memory) as a new kind of non-volatile memories has received much attention from both academia and industry. While PCM has many new features, such as fast read speed, non-volatility, and low power consumption, how to use PCM at memory hierarchy still remains a problem. In addition, at present PCM chips and storage devices are not available. This makes it hard to evaluate PCM-related algorithms. Thus, we design a flexible simulator named DPHSim to provide a test bed for PCM-related studies. The unique features of DPHSim are manifold. (1) It supports various kinds of memory hierarchy, including DRAM-only, PCM-only, PCM as the cache of DRAM, and hybrid memory (PCM and DRAM are both used as main memory). (2) It provides flexible configuration options for workloads generation and system setting. (3) It offers user-friendly memory allocation APIs for users to simulate memory hierarchy and evaluate performance on DPHSim. After an overview on the features and architecture of DPHSim, we present a case study of DPHSim to demonstrate its feasibility and flexibility.