相变存储器写寿命延长关键技术研究进展

随着大数据分析应用时效性提升和“存储墙”问题日益突出，存储系统已成为当前计算机系统整体性能的瓶颈。以相变存储器（PCM）为代表的新型非易失性存储器（NVM）具有集成度高、功耗低、读写访问速度高、非易失、体积小和抗震等优良特性，已成为最具潜力的下一代存储设备。然而，写寿命有限是PCM实用化的一道障碍，如何通过减少写操作和磨损均衡以提升PCM使用寿命是当前的研究热点。从减少PCM写操作、均匀写操作分布以及在混合内存中的页面迁移等三个方面介绍了当前PCM写寿命延长技术的研究现状以及优缺点，最后探讨未来进一步改进PCM寿命可能的研究方向。

Review:Key techniques of write enduranceimprovement for phase change memory

With the increasing demand for timeliness in big data analytics and the prominent “memory wall” problem, the storage system becomes the bottleneck of performance improvement of the overall computer systems. The novel non volatile memory (NVM), especially phase change memory (PCM), has the advantages of high storage density, low power consumption, high read/write access speed, non volatility, small size and quakeproof ability. All these make PCM the most promising candidate for the next generation storage medium. Because of the limited write endurance of PCM, the researches on enhancing PCM lifetime by reducing write operations and performing wear leveling on storage cell attract great attention from academia and industry. We introduce key techniques of write endurance improvement from three aspects of reducing PCM write operations, uniform distribution of write count, and page migration based on hybrid memory. Furthermore, we discuss their advantages and disadvantages. Finally, future research directions of further improvement on PCM lifetime are pointed out and discussed.