Earlier this week Intel-Micron announced (see webcast here and here) a new, transistor-less NVM with 1000 time the speed (10µsec access time for NAND) of NAND [~10ns (nano-second) access times] and at 10X the density of DRAM (currently 16Gb/DRAM chip). They call the new technology 3D XPoint™ (cross-point) NVM (non-volatile memory).
In addition to the speed and density advantages, 3D XPoint NVM also doesn’t have the endurance problems associated with todays NAND. Intel and Micron say that it has 1000 the endurance of today’s NAND (MLC NAND endurance is ~3000 write (P/E) cycles).
At that 10X current DRAM density it’s roughly equivalent to todays MLC/TLC NAND capacities/chip. And at 1000 times the speed of NAND, it’s roughly equivalent in performance to DDR4 DRAM. Of course, because it’s non-volatile it should take much less power to use than current DRAM technology, no need for power refresh.
We have talked about the end of NAND before (see The end of NAND is here, maybe). If this is truly more scaleable than NAND it seems to me that the it does signal the end of NAND. It’s just a matter of time before endurance and/or density growth of NAND hits a wall and then 3D XPoint can do everything NAND can do but better, faster and more reliably.
3D XPoint technology
The technology comes from a dual layer design which is divided into columns and at the top and bottom of the columns are accessor connections in an orthogonal pattern that together form a grid to access a single bit of memory. This also means that 3D Xpoint NVM can be read and written a bit at a time (rather than a “page” at a time with NAND) and doesn’t have to be initialized to 0 to be written like NAND.
The 3D nature of the new NVM comes from the fact that you can build up as many layers as you want of these structures to create more and more NVM cells. The microscopic pillar between the two layers of wiring include a memory cell and a switch component which allows a bit of data to be accessed (via the switch) and stored/read (memory cell). In the photo above the yellow material is a switch and the green material is a memory cell.
A memory cell operates by a using a bulk property change of the material. Unlike DRAM (floating gates of electrons) or NAND (capacitors to hold memory values). As such it uses all of the material to hold a memory value which should allow 3D XPoint memory cells to scale downwards much better than NAND or DRAM.
Intel and Micron are calling the new 3D XPoint NVM storage AND memory. That is suitable for fast access, non-volatile data storage and non-volatile processor memory.
3D XPoint NVM chips in manufacturing today
First chips with the new technology are being manufactured today at Intel-Micron’s joint manufacturing fab in Idaho. The first chips will supply 128Gb of NVM and uses just two layers of 3D XPoint memory.
Intel and Micron will independently produce system products (read SSDs or NVM memory devices) with the new technology during 2016. They mentioned during the webcast that the technology is expected to be attached (as SSDs) to a PCIe bus and use NVMe as an interface to read and write it. Although if it’s used in a memory application, it might be better attached to the processor memory bus.
The expectation is that the 3D XPoint cost/bit will be somewhere in between NAND and DRAM, i.e. more expensive than NAND but less expensive than DRAM. It’s nice to be the only companies in the world with a new, better storage AND memory technology.
Over the last 10 years or so, SSDs (solid state devices) all used NAND technologies of one form or another, but after today SSDs can be made from NAND or 3D XPoint technology.
Some expected uses for the new NVM is in gaming applications (currently storage speed and memory constrained) and for in-memory databases (which are memory size constrained). There was mention on the webcast of edge analytics as well.
Welcome to the dawn of a new age of computer storage AND memory.
Photo Credits: (c) 2015 Intel and Micron, from Intel’s 3D XPoint website