3D XPoint

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3D Cross Point 2 layer diagram

3D XPoint (pronounced three dee cross point[1]) is a non-volatile memory (NVM) technology developed jointly by Intel and Micron Technology. It was announced in July 2015 and is available on the open market under brand names Optane (Intel) and subsequently QuantX (Micron) since April 2017.[2] Bit storage is based on a change of bulk resistance, in conjunction with a stackable cross-gridded data access array.[3][4] Initial prices are less than dynamic random-access memory (DRAM) but more than flash memory.[5]

As a non-volatile memory, 3D XPoint has a number of features that distinguish it from other currently available RAM and NVRAM. Although the first generations of 3D XPoint were not especially large or fast, as of 2019 3D XPoint is used to create some of the fastest SSDs available, with small-write latency (the hardest type of task for most SSDs, sometimes described as "worst case" or "murderously" hard[6]) being an order of magnitude faster than any preceding enterprise SSD. 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, that allow it to be used as a caching or acceleration disk, and it is also fast enough to be used as non-volatile RAM (NVRAM) in a DIMM package.

History[edit]

Development[edit]

Development of 3D XPoint began around 2012.[7] Intel and Micron had developed other non-volatile phase-change memory (PCM) technologies previously;[note 1] Mark Durcan of Micron said 3D XPoint architecture differs from previous offerings of PCM, and uses chalcogenide materials for both selector and storage parts of memory cell that are faster and more stable than traditional PCM materials like GST.[9] But today, it is thought of as a subset of ReRAM.[10]

By 2015, full details of the technology had not been given by Intel or Micron, though the technology is apparently not based on electrons.[11] 3D XPoint has been stated to use electrical resistance and to be bit addressable.[12] Similarities to the resistive random-access memory under development by Crossbar Inc. have been noted, but 3D XPoint uses different storage physics.[7] 3D XPoint developers indicate that it is based on changes in resistance of the bulk material.[3] Intel CEO Brian Krzanich responded to ongoing questions on the XPoint material that the switching was based on "bulk material properties".[4] Intel has stated that 3D XPoint does not use a phase-change or memristor technology,[13] although this is disputed by independent reviewers.[14]

Media reports comment that as of April 2016, no other supplier had developed a working resistive RAM or phase-change memory technology that was sampling and matched 3D XPoint's performance and endurance.[15]

Initial production[edit]

In mid 2015, Intel announced the Optane brand for storage products based on 3D XPoint technology.[16] Micron (using the QuantX brand) estimated the memory to be sold for about half the price of dynamic random-access memory (DRAM), but four to five times the price of flash memory.[17] 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. They stack two 64 Gbit planes.[7][18] In early 2016 mass production of the chips was expected in 12 to 18 months.[19]

In early 2016 IM Flash announced that the first generation of solid-state drives would achieve 95000 IOPS throughput with 9 microsecond latency.[19] This low latency significantly increases IOPS at low queue depths for random operations. At Intel Developer Forum 2016, Intel demonstrated PCI Express (PCIe) 140GB development boards showing 2.4–3× improvement in benchmarks compared to PCIe NAND flash solid-state drives (SSDs).[20] On March 19, 2017, Intel announced their first product: a PCIe card available in the second half of 2017.[21][22]

Reception[edit]

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.

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",[23] 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.[6] ServeTheHome concluded in 2017 that in read, write and mixed tests, Optane SSDs were consistently around 2.5× as fast as the best Intel datacentre SSDs which had preceded them, the P3700 NVMe.[24] AnandTech noted that consumer Optane based SSDs were similar in performance to the best non-3D-XPoint SSDs for large transfers, with both being "blown away" by the large transfer performance of enterprise Optane SSDs.[25]

Compatibility[edit]

Intel[edit]

Intel distinguishes between "Intel Optane Memory" and "Intel Optane SSDs". As a memory component, Optane requires specific chipset and CPU support.[26] As an ordinary SSD, Optane is broadly compatible with a very wide range of systems, and its main requirements are much like any other SSD – ability to be plugged into the hardware, operating system, BIOS/UEFI and driver support for NVMe, and adequate cooling.[27]

  • As a standards-based NVMe-PCIe SSD: Optane devices can be used as the storage element of an ordinary solid-state drive (SSD), typically in M.2 card format, NVMe PCI Express format, or U.2 standalone format. When Optane is used as an ordinary SSD (in any of these formats), its compatibility requirements are the same as for any traditional SSD. Therefore compatibility depends only upon whether the hardware, operating system and drivers can support NVMe and similar SSDs. Optane SSDs are therefore compatible with a wide range of older and newer chipsets and CPUs (including non-Intel chipsets and CPUs).
  • As a memory or on-board acceleration device: Optane devices can also be used as NVDIMM (non volatile main memory) or for certain kinds of caching or accelerating roles, but unlike general SSD roles, this requires newer hardware, since the chipset and motherboard must be designed to work specifically with Optane in those roles.

Micron[edit]

See also[edit]

Notes[edit]

  1. ^ Intel and Numonyx presented 64 Gb stackable PCM chips in 2009.[8]

References[edit]

  1. ^ "3D XPoint Technology Revolutionizes Storage Memory", YouTube (infomercial video), Intel
  2. ^ "Intel Launches Optane Memory M.2 Cache SSDs for Consumer Market". AnandTech. 27 March 2017. Retrieved 13 November 2017.
  3. ^ a b Clarke, Peter (28 July 2015), "Intel, Micron Launch "Bulk-Switching" ReRAM", EE Times, "The switching mechanism is via changes in resistance of the bulk material," was all Intel would add in response to questions sent via email.
  4. ^ a b Merrick, Rick, "Intel's Krzanich: CEO Q&A at IDF", EE Times, p. 2
  5. ^ Evangelho, Jason (July 28, 2015). "Intel and Micron Jointly Unveil Disruptive, Game-Changing 3D XPoint Memory, 1000x Faster than NAND". Hot Hardware. Intel's Rob Crooke explained, 'You could put the cost somewhere between NAND and DRAM.'
  6. ^ a b "Intel Optane SSD 900P 256GB Performance Testing". Tom's Hardware. 4 December 2017. Retrieved 15 April 2019.
  7. ^ a b c Clarke, Peter (28 July 2015), "Intel, Micron Launch "Bulk-Switching" ReRAM", EE Times
  8. ^ McGrath, Dylan (28 Oct 2009), "Intel, Numonyx claim phase-change memory milestone", EE Times
  9. ^ Clarke, Peter (31 July 2015), "Patent Search Supports View 3D XPoint Based on Phase-Change", EE Times
  10. ^ "Partnership Puts ReRAM in SSDs". EE Times. 2017-09-27.
  11. ^ Neale, Ron (14 Aug 2015), "Imagining What's Inside 3D XPoint", EE Times
  12. ^ Hruska, Joel (29 July 2015). "Intel, Micron reveal Xpoint, a new memory architecture that could outclass DDR4 and NAND". ExtremeTech.
  13. ^ Mellor, Chris (28 July 2015). "Just ONE THOUSAND times BETTER than FLASH! Intel, Micron's amazing claim". The Register. An Intel spokesperson categorically denied that it was a phase-change memory process or a memristor technology. Spin-transfer torque was also dismissed
  14. ^ Malventano, Allyn (2 June 2017). "How 3D XPoint Phase-Change Memory Works". PC Perspective. Retrieved 8 June 2017.
  15. ^ By Chris Mellor, The Register. “Goodbye: XPoint is Intel's best exit from NAND production hell.” April 21, 2016. April 22, 2016.
  16. ^ Smith, Ryan (18 Aug 2015), "Intel Announces Optane Storage Brand For 3D XPoint Products", AnandTech
  17. ^ Mearian, Lucas (August 9, 2016). "Micron reveals marketing details about 3D XPoint memory QuantX: Intel, Micron may have made a mistake announcing 3D XPoint a year ago". Computer World. Retrieved March 31, 2017.
  18. ^ Smith, Ryan (18 August 2015), "Intel Announces Optane Storage Brand For 3D XPoint Products", Anandtech, products will be available in 2016, in both standard SSD (PCIe) form factors for everything from Ultrabooks to servers, and in a DIMM form factor for Xeon systems for even greater bandwidth and lower latencies. As expected, Intel will be providing storage controllers optimized for the 3D XPoint memory
  19. ^ a b Merrick, Rick (14 Jan 2016), "3D XPoint Steps Into the Light", EE Times
  20. ^ Cutress, Ian (26 August 2016). "Intel's 140GB Optane 3D Xpoint PCIe SSD Spotted at IDF". Anandtech. Retrieved 26 August 2016.
  21. ^ Bright, Peter (March 19, 2017). "Intel's first Optane SSD: 375GB that you can also use as RAM". Ars Technica. Retrieved March 31, 2017.
  22. ^ Figas, Jon (March 19, 2017). "Intel's first hyper-fast 3D drive is meant for servers". En Gadget. Retrieved March 31, 2017.
  23. ^ "Intel Optane SSD DC P4800X Review". Storage review. 31 July 2018. Retrieved 15 April 2019.
  24. ^ Robinson, Cliff (24 April 2017). "Intel Optane: Hands-on Real World Benchmark and Test Results". Serve thehome. Retrieved 15 April 2019.
  25. ^ Tallis, Billy. "The Intel Optane Memory (SSD) Preview: 32GB of Kaby Lake Caching". Anandtech. Retrieved 15 April 2019.
  26. ^ "Intel Optane Memory: Before You Buy, Key Requirements". Intel. Retrieved 15 April 2019.
  27. ^ "System Requirements for an Intel Optane SSD 900P Series Drive". Intel. Retrieved 15 April 2019.

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