3D XPoint

[1] Bit storage is based on a change of bulk resistance, in conjunction with a stackable cross-grid data access array, using a phenomenon known as Ovonic Threshold Switch (OTS).

As the memory is inherently fast, and byte-addressable, techniques such as read-modify-write and caching used to enhance traditional SSDs are not needed to obtain high performance.

In addition, chipsets such as Cascade Lake are designed with inbuilt support for 3D XPoint,[citation needed] which allows it to be used as a caching or acceleration disk, and it is also fast enough to be used as non-volatile RAM (NVRAM) or persistent memory in a DIMM package.

[15] Similarities to the resistive random-access memory under development by Crossbar Inc. have been noted, but 3D XPoint uses different storage physics.

[18] According to reverse engineering firm TechInsights, 3D XPoint uses germanium-antimony-tellurium (GST) with low silicon content as the data storage material which is accessed by ovonic threshold switches (OTSes)[19][20] made of ternary phased selenium-germanium-silicon with arsenic doping.

[23] Initially, a wafer fabrication facility in Lehi, Utah, operated by IM Flash Technologies LLC (an Intel-Micron joint venture) made small quantities of 128 Gbit chips in 2015.

[25] In early 2016, IM Flash announced that the first generation of solid-state drives would achieve 95000 IOPS throughput with 9 microsecond latency.

[27][28] Despite the initial lukewarm reception when first released, 3D XPoint – particularly in the form of Intel's Optane range – has been highly acclaimed and widely recommended for tasks where its specific features are of value, with reviewers such as Storage Review concluding in August 2018 that for low-latency workloads, 3D XPoint was producing 500,000 4K sustained IOPS for both reads and writes, with 3–15 microsecond latencies, and that at present "there is currently nothing [else] that comes close",[29] while Tom's Hardware described the Optane 900p in December 2017 as being like a "mythical creature" that must be seen to be believed, and which doubled the speed of the best previous consumer devices.

3D Cross Point 2 layer diagram
Intel Optane in M.2 card format
Optane 900p sequential mixed read-write performance, compared to a wide range of well reputed consumer SSDs. The graph shows how traditional SSD's performance drops sharply to around 500–700 MB/s for all but nearly-pure read and write tasks, whereas the 3D XPoint device is unaffected and consistently produces around 2200–2400 MB/s throughput in the same test. Credit: Tom's Hardware .