Intel, Micron's 3D XPoint Memory Could Change PC, Server Design

Intel and Micron yesterday announced 3D XPoint memory, a non-volatile memory which they said can deliver 1,000 times the speed of NAND flash and 10 times the density of traditional DRAM memory.

If the companies can deliver this memory in reasonable quantity at a reasonable price next year, as they promised, this could really change a lot of the way we do computing.

The new memory—pronounced 3D crosspoint—was announced by Mark Durcan, CEO of Micron Technology, and Rob Crooke, senior vice president and general manager of Intel's Non-Volatile Memory Solutions Group. They explained that 3D XPoint uses new materials which change properties, as well as a new crosspoint architecture that uses thin rows of metal to create a "screen door" pattern that enables the device to directly access each cell of memory, which should make it much faster than today's NAND flash. (These metal interconnects used to address memory cells are often referred to as wordlines and bitlines, though the terms weren't used in the announcement.)

The initial memory chips, due out in 2016, are slated to be manufactured at the company's joint venture fab in Lehi, Utah, in a dual-layer process that results in a 128GB chip—about equal in capacity to the latest NAND flash chips. Yesterday, the two executives displayed a wafer of the new chips.

Crooke called 3D XPoint memory a "fundamental game changer," and said it was the first new type of memory introduced since NAND flash in 1989. (That's debatable—a variety of companies have announced new types of memory, including other phase-change or resistive memories—but no one has shipped these in large capacities or volume.) "This is something many people thought was impossible," he said.

Effectively, this seems to fit in a gap between DRAM and NAND flash, offering speed that is closer to DRAM (although probably not quite as fast, since the companies didn't give actual numbers) with the density and non-volatility characteristics of NAND, at a price somewhere in between; recall that NAND is much less expensive than DRAM for the same capacity. You could see this acting as a much faster but more expensive replacement for flash in some applications; as a slower but much larger replacement for DRAM in others; or as another tier of memory between DRAM and NAND flash. Neither company discussed products—each will offer their own, based on the same parts coming out of the factory. But my guess is we'll see a range of products aimed at different markets.

Crooke said 3D XPoint could be particularly useful inside in-memory databases, as it can store much more data than DRAM and is non-volatile, and assist in such functions as faster machine startup and recovery. He also talked about connecting such chips to a larger system using the NVM Express (NVMe) specifications over PCIe connections.

Durcan talked about applications like gaming, where he noted the number of today's games that show a video while loading data for the next scene, something this memory could potentially alleviate. Durcan also mentioned applications like simulation in high-performance computing, pattern-recognition, and genomics.

3D XPoint Memory Diagram(3D XPoint Memory Diagram)

The pair didn't provide much technical information about 3D XPoint memory, other than one basic diagram and mention of a new memory cell and switch. In particular, they didn't discuss the new materials involved beyond confirming that the operation involved a change in the material's resistivity, although in a question-and-answer session they said it was different from other phase change materials that had been introduced in the past. Crooke did say he believed the technology was "scalable"—able to grow in density, apparently by adding more layers to the chip.

Other companies have been talking about new memories for years. Numonyx, which was originally formed by Intel and ST Microelectronics and later acquired by Micron, introduced a 1GB phase change memory in 2012. Other companies, including IBM and Western Digital's HGST, have shown demonstrations of systems based on that material, though Micron is no longer offering it. HP has long been talking about memristor, and newer start-ups like Crossbar and Everspin Technologies have spoken of new non-volatile memories as well. Other large volume memory companies, such as Samsung, have also been working on new non-volatile memory. None of these companies has yet to ship non-volatile memory with large capacities (such as the 3D XPoint's 128GB size) at large volume, but of course, Intel and Micron have only announced, not shipped.

Neither Intel nor Micron talked about the specific products they would ship, but I wouldn't be surprised if we heard more as we approach the SC15 Supercomputing show in November, where Intel is expected to formally launch its Knights Landing processor, since high-performance computing would seem to be a likely early market.

Most people in the memory industry have long believed there is room for something between DRAM and NAND flash. If indeed 3D XPoint lives up to its promise, this will be the beginning of a significant change in the architecture of servers, and eventually, PCs.