The number and diversity of consumer devices are growing rapidly, alongside their target applications' memory consumption. Unfortunately, DRAM scalability is becoming a limiting factor to the available memory capacity in consumer devices. As a potential solution, manufacturers have introduced emerging non-volatile memories (NVMs) into the market, which can be used to increase the memory capacity of consumer devices by augmenting or replacing DRAM. Since entirely replacing DRAM with NVM in consumer devices imposes large system integration and design challenges, recent works propose extending the total main memory space available to applications by using NVM as swap space for DRAM. However, no prior work analyzes the implications of enabling a real NVM-based swap space in real consumer devices. In this work, we provide the first analysis of the impact of extending the main memory space of consumer devices using off-the-shelf NVMs. We extensively examine system performance and energy consumption when the NVM device is used as swap space for DRAM main memory to effectively extend the main memory capacity. For our analyses, we equip real web-based Chromebook computers with the Intel Optane SSD, which is a state-of-the-art low-latency NVM-based SSD device. We compare the performance and energy consumption of interactive workloads running on our Chromebook with NVM-based swap space, where the Intel Optane SSD capacity is used as swap space to extend main memory capacity, against two state-of-the-art systems: (i) a baseline system with double the amount of DRAM than the system with the NVM-based swap space; and (ii) a system where the Intel Optane SSD is naively replaced with a state-of-the-art (yet slower) off-the-shelf NAND-flash-based SSD, which we use as a swap space of equivalent size as the NVM-based swap space.

翻译：随着消费设备数量与种类的快速增长，其目标应用对内存的消耗也日益增加。然而，DRAM的可扩展性正成为制约消费设备可用内存容量的瓶颈。作为一种潜在解决方案，制造商已将新兴的非易失性存储器（NVM）推向市场，通过增强或替代DRAM来提升消费设备的内存容量。由于在消费设备中完全用NVM替代DRAM会带来巨大的系统集成与设计挑战，近期研究提出利用NVM作为DRAM的交换空间来扩展应用程序可用的主存空间。但尚无前期工作分析在真实消费设备中启用基于实际NVM的交换空间所产生的影响。本文首次分析了使用商用NVM扩展消费设备主存空间的效果。我们全面考察了将NVM设备作为DRAM主存交换空间（以有效扩展主存容量）时的系统性能与能耗情况。为进行实验分析，我们为基于网络的实际Chromebook设备配备了英特尔傲腾SSD——一种采用最新低延迟NVM技术的固态硬盘。我们将使用NVM交换空间（即利用英特尔傲腾SSD容量作为交换空间扩展主存）的Chromebook上运行交互式工作负载时的性能与能耗，与两种先进系统进行对比：(i) 配备两倍于NVM交换空间系统DRAM容量的基线系统；(ii) 将英特尔傲腾SSD简单替换为同等容量但速度较慢的商用NAND闪存SSD作为交换空间的系统。