Analyzing Intel-Micron 3D XPoint: The Next Generation Non-Volatile Memory
by Kristian Vättö, Ian Cutress & Ryan Smith on July 31, 2015 11:00 AM ESTFinal Thoughts
3D XPoint has a lot to chew on. There hasn't been an announcement this big in the memory industry since the invention of NAND in 1989 and while DRAM and NAND have improved and scaled a lot over the decades, 3D XPoint is really a new class of memory. It's fast, durable, scalable and non-volatile, whereas DRAM and NAND each only meet two of these criteria. It fills the niche between DRAM and NAND by taking the best characteristics of both technologies and creating a memory unlike anything we have seen before.
The significance of the announcement isn't just the new memory technology, but that it's actually in production with volume shipments scheduled for next year. Intel and Micron have succeeded in bringing a concept from a lab to an actual fab, which is by far the most difficult part in any new semiconductor technology. Something that works well in a lab may not be mass producible at all, but Intel and Micron made the necessary investments to develop new material compounds and surrounding technologies to turn 3D XPoint into a real product. It will be interesting to see how the other DRAM and NAND vendors respond because the memory industry is one where you don't want your rivals to have something you don't for an extended period of time.
However, it's clear that 3D XPoint isn't a true DRAM or NAND successor and Intel and Micron aren't trying to position it as such. DRAM will still have its market in high performance applications that require the latency and endurance that 3D XPoint can't offer. Our early cost analysis also suggests that 3D XPoint isn't as dense as planar NAND, let alone 3D NAND, but by having the ability to scale both vertically and horizontally 3D XPoint may have the potential to replace 3D NAND in the long run.
Looking further into the future, 3D XPoint isn't the only technology Intel and Micron are cooking. If the two stay on schedule, we should be hearing about their other new memory technology in roughly two years. As 3D XPoint seems to be more suitable as a 3D NAND replacement, the second new technology might be one that is capable of taking DRAM's place in the long run.
All in all, it's impossible to think of all the possible applications that 3D XPoint will have in the future because it's a technology that hasn't existed before. I don't think it's an overstatement to say that 3D XPoint has the potential to change modern computer architectures and the way we see computing, but that transition won't happen overnight and will likely require competing technologies from other vendors to fulfill the demand. What is clear, though, is that Intel and Micron are leading us to a new era of memory and computing next year.
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Pork@III - Friday, July 31, 2015 - link
1000X1000X10=3 Touch my crazy math! "Analyze This"Wwhat - Saturday, August 8, 2015 - link
Didn't intel slides on future CPU's talk about the new RAM? That would mean they might create their own market and there is no need to hope someone is interested really, if it's architecturally a (semi-)requirement for intel based systems.Wwhat - Saturday, August 8, 2015 - link
Oh excuse me, wasn't meant to be a reply but a standalone comment.Russ.Dill@gmail.com - Friday, July 31, 2015 - link
I was really excited about this article due to the leadup on Twitter. But I'm really disappointed on the coverage of the technology.I think Ian has a bit of confirmation bias going into this and did not examine PCM closely enough:
> During the discussions after the announcement, we were told
> categorically that this is not a phase change material, eliminating
> one potential avenue that it might be the change in the crystal
> structure of the cell producing the resistance change.
Here's the portion of the webcast:
https://www.youtube.com/watch?v=VsioS35D-HY&t=...
"So…so let me take the first piece while Rob you jump in. First…first of all you shouldn't think of this as NAND or DRAM. You should think of it as a whole new class of memory. It…it…it…it really does fill it's own unique spot. Now it can be used in more of a storage type of application or it can be used more as a system main memory and we think it will be used as both. Uh…uh f…for different applications and different reasons. Um, but it really kinda fits in that…in that unique spot.
Now rel…I'm not familiar with sigma RAM I'm sorry maybe…maybe Rob is, but…but relative to…to phase change which has been the market before and which Micron has some experience with in the past. Uh, again, this is uh, this is a, this is a…a very different architecture in terms of the place it fills in the…in the…in the memory hierarchy because it has these…these dramatic improvements, uh, in speed, uh, and…and volatility and, uh, performance."
I don't view that as a categorical denial that it's PCM. Just that it's a different architecture than the PCM product had out before, which it is. This is cross point. And there is a lot of hesitation in this response and it seems like rather than trying to answer the technology question, he goes back on message.
Along with patents, linkedin profiles (Employee confirms working on a 2xnm PCM 3D cross-point chip since January 2014, see Giulio Albini), and the mentions in the webcast of "property change" and "bulk material".
Russ.Dill@gmail.com - Friday, July 31, 2015 - link
The interesting thing is that 2xnm PCM cross point technology has been on the roadmap for a while, but in 2014, mention of PCM was phased out. The 2014/2015 materials still mention "other technologies" though. It could be that the technology failed. It seems more likely that there is some legal or corporate strategy for not mentioning the technology.2013 Fall and Summer slides: http://i.imgur.com/pAHeUPH.png
Ian Cutress - Friday, July 31, 2015 - link
We had a separate question and answer session with Greg Matson, SSD Director at Intel. When specifically asked if it was PCM, he said he could confirm that it was not.Russ.Dill@gmail.com - Friday, July 31, 2015 - link
I'm guessing this Q/A session was not recorded, can you give an actual quote? Are they just arguing semantics and claiming that it is PCMS?Ian Cutress - Friday, July 31, 2015 - link
OK now that I'm at a computer I can respond properly.Kristian attended the event live, I was at the UK briefing led by Greg Matson, so all questions on my end went through him with other press based in the UK, so no it was not recorded. It was specifically asked 'Is this Phase Change?' and he responded 'I can confirm it is not Phase Change'. The other journalist at that Q&A that I've seen pick up on this was the one that asked the question, Chris Mellor from The Register. Check his tweets on the subject as a double confirmation:
https://twitter.com/Chris_Mellor/status/6267342455...
https://twitter.com/Chris_Mellor/status/6267347543...
If you read through Chris' piece on XPoint, he comes to similar conclusions based that a 64Mb phase change demo with an ovonic switch last year was different to Micron's slide demonstration of XPoint with a diode-based selector.
So standard PCM/PCMS revolves around bulk crystal structure changes and metastable forms to differentiate resistive states, hence the 'phase' part of phase change. Arguably conductive bridging is also a change in phase, from a charged ion to a conducting metal, although is not specifically called phase change as such. It could also not necessarily be called a 'bulk change' as mentioned by Intel, although if the electrolyte layer is thin it would certainly act like bulk between the electrodes.
PCM, as of last year, was also considered one of the front runners leading into the technology based on information released although there have been reservations based on the currentneeded to transition current materials and the respective heat. Given Micron's investor briefing slides, conductive bridging is still perhaps the most likely, especially given how Matson answered the PCM question with an affirmative no. I understand that a few analysts have stated is PCM, given the watchful eye on patents and so forth, but coming direct from the source is hard to ignore with all the other suggestions.
As Kristian points out, Micron's investor roadmap points to a second technology in a couple of years also entering the market. If this isn't PCM, that could be, or vice versa. Or even STT.
Just for the record I'm merely trying to pinpoint where the evidence leads me, rather than introduce any sort of bias here. Without a direct SEM or quote from Intel, we can't be sure. Both PCM and CB can be done with many different materials, and I'd hazard a guess there are combinations that haven't been made public. So we're still talking about general methodology rather than specific physical interations between named structures.
If anyone comes up with anything else, I'd be glad to hear and read it.
Russ.Dill@gmail.com - Friday, July 31, 2015 - link
They have two future memory tech on their timeline, A and B. Perhaps we are seeing A now, and B is phase change.Russ.Dill@gmail.com - Friday, July 31, 2015 - link
BTW, I am still leaning very strongly towards PCM. It of course seems unlikely in the highest degree that Matson could of misspoken on something so basic. Maybe I'm not familiar enough with the tech industry, but it seems so very strange that they are so cagey on the tech. There must be a very strongly company wide memo from legal. They seem to be able to confirm that it is a resistive memory element, but nothing beyond that. So from that aspect, it seems strange that someone would be willing to go on record stating what type of resistive memory element it is not.Given the number of companies with promising cross point style resistive memory architectures (many of them PCM, eg, ST), and the patent warchests to go with them, there is likely to be a legal battle that will make the whole RAMBUS thing seem like it was a small claims case.
I wonder what event is gating release of tech details. Is it a legal agreement? A patent date? A pending legal action?