SHF: Small: Energy-Efficient Memory Subsystems for the Many-Core Era

内存子系统消耗的能量作为整体服务器能量消耗的一小部分在增加。预计即将到来的低功耗、字节可寻址的永久存储器技术，即相变RAM(PC-RAM)和自旋转移扭矩RAM(STT-RAM)，可能在节省服务器能量方面发挥主要作用。这些技术远远优于Flash，最有趣的是，实际上也可能取代DRAM。研究将通过将这些技术与DRAM相结合来研究混合存储子系统，以及无DRAM的存储子系统。调查的结果将是：(1)关于PC-RAM和STT-RAM的知识及其潜在的优势和限制；(2)内存控制器和操作系统技术的集合，用于使用这些技术来节约能源，同时将性能下降限制在用户定义的限制内；以及(3)可供其他人在调查内存和能源问题时使用的模拟和操作系统基础设施。这项工作可以促进内存子系统设计和节能的新方向，一个可以对未来服务器的设计产生深远影响的方向。

The energy consumed by the memory subsystem is increasing as a fraction of the overall server energy consumption. It is anticipated that upcoming low-power, byte-addressable, persistent-memory technologies, namely Phase-Change RAM (PC-RAM) and Spin-Transfer Torque RAM (STT-RAM), are likely to play a major role in conserving server energy. These technologies are far superior to Flash and, most interestingly, may actually replace DRAM as well.The research will study hybrid memory subsystems by combining these technologies and DRAM, as well as DRAM-free memory subsystems. The outcomes of this investigation will be: (1) a body of knowledge about PC-RAM and STT-RAM and their potential benefits and limitations; (2) a collection of memory controller and operating system techniques for using these technologies to conserve energy, while bounding performance degradation to user-defined limits; and (3) a simulation and operating system infrastructure that can be used by others in their investigations of memory and energy issues. This work can promote a new direction in memory subsystem design and energ conservation, one that can have a profound impact on the design of future servers.