Basic Performance Measurements of the Intel Optane DC Persistent Memory Module Or: It’s Finally Here! How Fast is it? Joseph Izraelevitz Jian Yang Lu Zhang Juno Kim Xiao Liu Amirsaman Memaripour Yun Joon Soh Zixuan Wang Yi Xu Subramanya R. Dulloor Jishen Zhao Steven Swanson* Computer Science & Engineering University of California, San Diego arXiv:1903.05714v3 [cs.DC] 9 Aug 2019 *Correspondence should be directed to
[email protected]. Copyright © 2019 the authors. 1 2019-08-09 7041bc9 Abstract After nearly a decade of anticipation, scalable nonvolatile memory DIMMs are finally commercially available with the release of the Intel® Optane™ DC Persistent Memory Module (or just “Optane DC PMM”). This new nonvolatile DIMM supports byte-granularity accesses with access times on the order of DRAM, while also providing data storage that survives power outages. This work comprises the first in-depth, scholarly, performance review of Intel’s Optane DC PMM, exploring its capabilities as a main memory device, and as persistent, byte-addressable memory exposed to user-space applications. For the past several months, our group has had access to machines with Optane DC memory and has investigated the Optane DC PMM’s performance characteristics. This report details the chip’s performance under a number of modes and scenarios, and across a wide variety of both micro- and macro-scale benchmarks. In total, this report represents approximately 330 hours of machine time. Optane DC memory occupies a tier in-between SSDs and DRAM. It has higher latency (346 ns) than DRAM but lower latency than an SSD. Unlike DRAM, its bandwidth is asymmetric with respect to access type: for a single Optane DC PMM, its max read bandwidth is 6.6 GB/s, whereas its max write bandwidth is 2.3 GB/s.