After a big 3D XPoint launch one year ago almost anyone would expect for Intel to have had a lot of exciting new news to share about the technology at last week’s Intel Developer Forum (IDF). Those who were watching for that, though, were in for a disappointment.
For readers who don’t remember, Intel and its partner, chipmaker Micron Technology, announced a new memory layer in July 2015 that would enable in-memory databases to expand well beyond the constraints posed by standard DRAM memory. The pair also boasted the additional benefit of being nonvolatile or persistent – data would not be lost if the power failed. This technology promised to open new horizons in the world of computing.
Intel devoted a lot of effort to promotion and education during the following month’s IDF, and even demonstrated a prototype 3D XPoint SSD that performed seven to eight times as fast as Intel’s highest-performance existing NAND flash SSD – the DC S3700. Although a DIMM form factor was disclosed, no prototypes were on hand. Both were given the brand name “Optane”.
How short is that list? Interestingly, Intel and Micron have different lists. The Micron list, shown in this post’s graphic (click to enlarge), cites seven types: “Ram” (showing a vacuum tube), PROM, SRAM, DRAM, EPROM, NOR flash, and NAND flash. Intel’s list adds magnetic bubble memory, making it eight. (Definitions of these names appear in another Memory Guy blog post.)
The Memory Guy finds both lists puzzling in that they left out a number of important technologies.
For example, why did Intel neglect EEPROM, which is still in widespread use? EEPROMs (or E²PROMs) are not only found in nearly every application that has a serial number (ranging from WiFi routers to credit cards), requires calibration (like blood glucose monitoring strips and printer ink cartridges), or provides operating parameters (i.e. the serial presence detect – SPD – in DRAM DIMMs), but they still ship in the billions of units every year. In its time EEPROM was an important breakthrough. Over the years EEPROM has had a much greater impact than has PROM.
And, given that both companies were willing to include tubes, a non-semiconductor technology, why did both Continue reading
Micron and Intel hosted an event in San Francisco Tuesday, July 28, to introduce a new memory technology that they have named “3D XPoint”. This technology was explained to be “up to 1,000 times faster, with 1,000 times the endurance of NAND flash” while being significantly cheaper than DRAM.
Some technical details:
- 3D XPoint is a “Fundamentally Different Technology” than current memory types. It’s an ReRAM that uses material property changes for bit storage where both DRAM and NAND use charge to store a bit
- The chip currently stores 128Gb in two stacked planes of 64Gb each, storing a single bit per cell
- Today’s densest production NAND flash chips store 128GB by using MLC, so this chip actually has twice as many bit cells as any production NAND flash
- The companies do not see a clear limit to the number of planes they can stack, but are optimistic about this
- The bulk mechanism can be used to store multiple bits on a single cell (MLC)
- Today’s chip is made using a 20nm process, but can scale well past that
- There is no clear limit of how far the technology can be scaled
- It’s 1,000 times faster than NAND flash and offers 1,000 times NAND’s endurance
- It’s 10 times as dense as today’s “Conventional Memory” (which I suppose to be DRAM)
- This is not intended to replace either NAND or DRAM, but to coexist as a new memory layer between NAND and DRAM
The companies claim that other Continue reading