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3D Xpoint memory: Faster-than-flash storage unveiled

bbc.com

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Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#51

Post by faragon »

minthd wrote: post #12

A guess: this uses memristors(i.e. rram). crossbar is a startup in the field, their site gives plenty of details about the tech. http://www.crossbar-inc.com/

I think this is not the memristor thing. I remember memristor-related posts in Slashdot (2008 [1], 2012 [2]), but the ones related to Intel + Micron (2014 [3], 2015 [4]) tell about "3D nand", which may be just NAND-flash using multiple layers with 3D interconnect. However, the speed and density claims make doubt if in reality this is or not the same as the memristor.

[1] http://hardware.slashdot.org/story/08/04/30/211228/memristor... [2] http://hardware.slashdot.org/story/12/07/25/2127229/the-hp-m... [3] http://hardware.slashdot.org/story/14/11/25/2027220/how-inte... [4] http://hardware.slashdot.org/story/15/03/26/2037221/micron-a...

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#52

Post by russdill »

russdill wrote: post #49
mmf wrote: post #42

I did research in the field from 2008 to 2013. The claims are always the same: faster than flash, denser than dram, lower power than both. Here's how to spot BS: first, the density claims are immaterial until they prove yield at a technology node same as dram's today. There are multiple billions investment between 180nm and high yield (and low mask count) 2xnm, no matter how cool is the new memory technology. Second,…

Actually you should be taking the claims very seriously. This has been an area Micron has been researching for decades. They've had a patent on the memory cell for about 11 years now (US6777705). Phase change memory has for a very long time been one of those just over the horizon technologies, but Micron has perfected it well enough to compete with NAND and partnered with Intel to bring it to market. This isn't somet…

Forward looking article from June with tons of analysis http://seekingalpha.com/article/3253655-intel-and-micron-the...

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#54

Post by jjoonathan »

mmf wrote: post #42

I did research in the field from 2008 to 2013. The claims are always the same: faster than flash, denser than dram, lower power than both. Here's how to spot BS: first, the density claims are immaterial until they prove yield at a technology node same as dram's today. There are multiple billions investment between 180nm and high yield (and low mask count) 2xnm, no matter how cool is the new memory technology. Second,…

> dram latency does not depend on the memory technology, rather it depends on the array size

Wait, what? You mean they are making us wait 10ns for row open and 10ns for row close just for shits and giggles? Or did you mean to say "bandwidth"? I'm confused (genuinely, not sarcastically).

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#55

Post by mmf »

jjoonathan wrote: post #54
mmf wrote: post #42

I did research in the field from 2008 to 2013. The claims are always the same: faster than flash, denser than dram, lower power than both. Here's how to spot BS: first, the density claims are immaterial until they prove yield at a technology node same as dram's today. There are multiple billions investment between 180nm and high yield (and low mask count) 2xnm, no matter how cool is the new memory technology. Second,…

> dram latency does not depend on the memory technology, rather it depends on the array size Wait, what? You mean they are making us wait 10ns for row open and 10ns for row close just for shits and giggles? Or did you mean to say "bandwidth"? I'm confused (genuinely, not sarcastically).

Not shits and giggles, it's access to the array: subarray and word line decoding plus sense amp time. Find me a technology that does not need all these and I'll bow to you (and invest in your startup :D).

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#56

Post by mmf »

zxcv123 wrote: post #50
mmf wrote: post #42

I did research in the field from 2008 to 2013. The claims are always the same: faster than flash, denser than dram, lower power than both. Here's how to spot BS: first, the density claims are immaterial until they prove yield at a technology node same as dram's today. There are multiple billions investment between 180nm and high yield (and low mask count) 2xnm, no matter how cool is the new memory technology. Second,…

Power consumption of DRAM is high, what are you talking about? DRAM requires constant refresh -- the whole reason DRAM can be high-density if because it is a 1-T cell with a trench capacitor -- but the capacitor needs to be refreshed on a synchronized basis (hence SDRAM) -- that was the big innovation. And yes, array size affects latency but so does the underlying process technology (much more so across technologies)…

As I did not have the numbers fresh in memory (apparently I needed a refresh ;) ) I googled for dram data sheet and got the first ddr3 PDF (Hynix). Quick, and very dirty math suggests that

-refresh power is on the order of milliwats per Gigabyte

-memory access is on the order of 0.1W per GB per second

For refresh power, let's face it: it's puny. Regarding the active power, I have yet to see anything (off chip and this size) that is better than that.

P.S. I did say active in my original post :)

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#57

Post by russdill »

minthd wrote: post #12

A guess: this uses memristors(i.e. rram). crossbar is a startup in the field, their site gives plenty of details about the tech. http://www.crossbar-inc.com/

No, this is not memristors (unless you consider PCM to be a memristor) and it has no relation to crossbar-inc.com. This is phase change memory.

https://www.google.com/search?q=site%3Amicron.com+%22cross-p...

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#58

Post by aidenn0 »

the8472 wrote: post #23
aidenn0 wrote: post #17

Earlier quoted context omitted.

I'd like to see a source for the "similar density to DRAM" my understanding is that it's an 8F2 footprint, and scaling it down to small process nodes is still problematic, even with spin-torque transfer. All that being said, there are people who make the exact same claims about RRAM as you quote for MRAM, which 3d-xpoint appears to be. Also note that you can buy MRAM parts right now, which are replacements for batter…

> my understanding is that it's an 8F2 footprint Where does that come from? From everything I've read is that its structure is fairly analogous to DRAM, "simply" replacing the capacitor with the magnetic tunnel junction, which has its component layers stacked vertically, thus not really taking up any extra space. > scaling it down to small process nodes is still problematic, even with spin-torque transfer. yeah, that…

>> my understanding is that it's an 8F2 footprint

> Where does that come from? From everything I've read is that its structure is fairly analogous to DRAM, "simply" replacing the capacitor with the magnetic tunnel junction, which has its component layers stacked vertically, thus not really taking up any extra space.

I did some searching; older references show an 8-12F2 size, for e.g. the Everspin parts. Grandis claims a 6F2 size which is indeed comparable to DRAM.

>> people who make the exact same claims about RRAM as you quote for MRAM, which 3d-xpoint appears to be.

> At least the xpoint incarnation still seems to be slower than DRAM according to that article, while MRAM is being offered as SRAM/battery-backed DRAM drop-in replacement.

Right, the product they are claiming they will manufacture next year is slower than DRAM and less dense than flash. (Frustratingly I couldn't find a reference for if they are talking about latency or throughput when they say "slower"; it makes a big difference for which applications will be hurt by the performance mismatch).

However, there doesn't appear (yet) to be a fundamental reason why resistive ram must always be slower than DRAM, nor a fundamental reason why they couldn't do MLC tricks with it, so you can't say all RRAM will be slower than DRAM and less dense than NAND.

Re: 3D Xpoint memory: Faster-than-flash storage unveiled

#60

Post by assface »

rasz_pl wrote: post #53

Dear Micron, brace for a mother of all patent lawsuits from HP.

> Dear Micron, brace for a mother of all patent lawsuits from HP.

Ignore this person. They don't know what they are talking about.

This is phase-change memory. It's been on everyone's radar for the last decade. HP is pushing their titanium oxide memristors. That's a completely different technology.

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