
Crossbar Resistive RAM stores a terabyte on a chip - iand
http://venturebeat.com/2013/08/05/crossbar-says-it-will-explode-the-60b-flash-memory-market-with-resistive-ram-which-stores-a-terabyte-on-a-chip/
======
GravityWell
_Crossbar believes it can write data to its chip at 140 megabytes per second,
compared to 7 megabytes a second for flash. Read performance is 17 megabytes
per second, with a random read latency of 30 nanoseconds._

The write performance sounds good, but the read performance seems very low.
Also I don't know where they get 7 megs per second for flash. Sounds like the
picked the worst performer to compare to.

I'd be more impressed if they had something on the market.

~~~
WatchDog
The numbers are fairly suspicious, they don't reference the density of the
flash they are benchmarking or if they are behind controllers.

Flash chips are generally multiplexed and behind a smart controller that
compresses and and caches data, which can greatly effect the throughput
numbers.

~~~
rossjudson
Lots of other stuff to know -- what's the BER (bit error rate), what's the
programming model (page erase, like flash)? How many simultaneous reads can
you push through? Writes? Can you halt an ongoing operation or change it mid-
stream?

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gr3yh47
" It could also perform its storage functions at 20 times lower power,
extending the battery life of devices using it to weeks, months, or years. "

no, reducing RAM power 20x does not extend battery life of devices to weeks.
Anything with a screen or active antenna will likely not see much of a
difference

~~~
megablast
I used to think the same, but with the new Intel chip, you can now get about
12 hours out of a macbook air.

~~~
alphakappa
Where does the extra battery life come from? The CPU? Graphics? Better RAM?
Better wifi/BT? Software improvements in the OS and apps to use power more
efficiently? Lower power screen?

Battery life is affected by such a multitude of components that it's hard to
extrapolate savings in one component to the battery life of the complete
device.

------
pfraze
> It can access that data 20 times faster than the best breed of flash memory

> could also perform its storage functions at 20 times lower power

> non-volatile

> 10 times the endurance of NAND flash chips that it could replace

If this is true, wow, but I have a hard time believing it.

~~~
31reasons
They haven't mentioned the price or may be I missed it. That may be the
important factor.

~~~
kcorbitt
They also don't compare the read speed (17 MB/s) to existing flash memory.
They showcase an amazing write speed, but most applications access data a lot
more frequently than they create it.

~~~
wging
They do _say_ "It can access that data 20 times faster than the best breed of
flash memory" but a rate of 17 MB/s means this is incorrect.

~~~
shenberg
They're probably referring to latency, which is very low (30ns). It still is
disingenuous, but that's marketing.

~~~
vlasta2
I guess it is more accurate to talk about latency, because throughput can
always be improved by accessing multiple cells in parallel.

------
guelo
According to the wikipedia article on RRAM there are several companies working
to bring this tech to market. [http://en.wikipedia.org/wiki/Resistive_random-
access_memory](http://en.wikipedia.org/wiki/Resistive_random-access_memory)

~~~
acqq
And according to this article, the companies that name their memristor variant
as something else do so because of the patents:

[http://www.eetimes.com/document.asp?doc_id=1262578](http://www.eetimes.com/document.asp?doc_id=1262578)

~~~
angersock
Aha! So, this _is_ memristor arrays?

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sillysaurus
Does anyone know if there has been progress in volatile memory tech? I'm
hoping for 1TB RAM chips with 10x faster access times than current RAM. It
will enable PC gaming to deliver unmatched immersive experiences, among other
applications.

~~~
rorrr2
Gaming is limited by the CPU/GPU, and a bit by the bandwidth in between. Not
by the RAM speed/latency.

~~~
RyanZAG
Not strictly true. Most algorithm choices in gaming can make trade offs
between CPU and RAM. If you increase available RAM, you can usually use
algorithms that are more RAM hungry and less CPU hungry for large speed
benefits.

~~~
rorrr2
If we're talking about game logic, I agree.

If we're talking about rendering beautiful complex worlds with post-processed
special effects, I disagree.

~~~
ajuc
In 1 TB of RAM you can keep without any compression 3d array 1000m * 1000m *
64m of voxels with 1 voxel being a cube 2 cm * 2 cm * 2 cm. And you can lookup
it randomly with negligible latency and do real time raytracing on it.

If that won't change games I don't know what can.

Besides GPUs will obviously also use this technology if it really works.

~~~
seanv
this needs to be higher up.. that's awesome to know! ... we might actually be
able to emulate the Ps3 on the computer! hah

~~~
Einherji
I don't know what is special about emulating a ps3 on a PC, most mainstream
PCs and GPUs are faster than the Power-PC based cell processor in the ps3 (an
8 year old console). Even the ps4 does not contain any better graphics
processing capabilities than a recent relatively high end PC.

------
MarcScott
Interesting to see that Samsung started mass production of their 3D NAND
memory yesterday.

[http://www.engadget.com/2013/08/05/samsung-ships-
first-3d-ve...](http://www.engadget.com/2013/08/05/samsung-ships-
first-3d-vertical-nand-flash/)

------
drcode
This article makes a lot of extraordinary claims. Extraordinary claims require
extraordinary evidence.

In this case, that means a reputable tech reporter from a reputable
publication has to say "this is the real deal" before these guys can be taken
seriously.

(I'm not doubting that they have any tech, it's just that they seem to be
promising something with no downsides, which in most cases means a marketing
team has spun out of control.)

~~~
Alex3917
"This article makes a lot of extraordinary claims. Extraordinary claims
require extraordinary evidence."

Does it? It just sounds like a normal memristor to me.

~~~
standel
Memristor does not seem to be normal neither. Is there any on the market?

~~~
wikiburner
No, but they've been expected to be on the market any day now for the past
year or two. HP's been doing tons of research and prep work in commercializing
them:

[http://www.engadget.com/2010/08/31/hp-labs-teams-up-with-
hyn...](http://www.engadget.com/2010/08/31/hp-labs-teams-up-with-hynix-to-
manufacture-memristors-plans-as/)

[http://www.wired.com/wiredenterprise/2012/07/hp-
memristors/](http://www.wired.com/wiredenterprise/2012/07/hp-memristors/)

~~~
Alex3917
"They've been expected to be on the market any day now for the past year or
two."

The last I heard was second quarter 2014 by HP, that's been the release date
for the last year or so. Supposedly they could release them now, but they are
trying to time the market for business reasons.

------
Symmetry
Given the graphic on the top a chip with 8 GByte at 77mm^2 I have no idea
where they're getting the "Terabyte on a chip" thing. Unless the mean a
Terabyte on a 200 mm _die_?

~~~
ars
They probably mean TB for the whole device, and each chip is smaller. This
could also be a picture of an earlier model.

~~~
solistice
Also they're stacking the device 3 dimensionally, so they could be referring
to 125 layers of 8gb RRAM, which would spit out the 1TB number.

------
joe_the_user
I remember memristers were supposed to do something like this.

Anyone have an idea if this is related or unrelated.

[http://en.wikipedia.org/wiki/Memristor](http://en.wikipedia.org/wiki/Memristor)

~~~
pfraze
As I understand it, one of the (more interesting) characteristics of
memristors is that they can do computation. They don't mention anything like
that here, so I doubt it.

~~~
Tuna-Fish
A memristor can be set up as a logic element that does computation, _or_ as a
memory storage element, just like a transistor (only persistent).

For some strange reason, the tech press took this to mean that a memristor
array can be dynamically reconfigured to act as logic or ram in the same
device. This is mostly false -- while yes, this kind of devices can be built
(with transistors, they are typically called field-programmable gate arrays,
or FPGAs), this requires you to be able to reconfigure not just the gates, but
all the _wiring_ that goes into them, meaning that a reconfigurable array has
to be more than an order of magnitude larger, and a few times slower than a
non-reconfigurable one.

You never want to use an FPGA for ram because you can get proper, non-
reconfigurable ram for (way) less than tenth of the cost. You never want to
use a fpga for logic if you can afford an asic, because you can be several
times faster with hard-baked logic.

Memristors will mean nice FPGAs that retain state on power down, but they will
_not_ mean a revolution of dynamically reconfiguring devices.

Oh, and memristor logic is slower than transistor logic (you can do with less
gates, but the gates switch slower) so the ability to use memristors for logic
elements will initially mostly be a win in memory devices where the necessary
logic to manage the device can be made out of the same structures the device
is made of.

~~~
pfraze
Thanks for clearing that up.

------
touristtam
maybe a more tech oriented article would have been preferable:
[http://www.theregister.co.uk/2013/08/05/crossbar_uncloaks_fa...](http://www.theregister.co.uk/2013/08/05/crossbar_uncloaks_fast_tiny_capacious_rram_part/)

(venturebeat sounds like a investor magazine to me)

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keerthiko
That is flipping amazing if true.

Also, that "Crossbar Chip Design" graphic made me chuckle. It is nearly
meaningless by itself, and is placed so far away from the context it's
discussed in, it almost remains that way unless you're trying to connect it.

~~~
redangstrom
Let's be cautiously optimistic. Every few years a new memory tech comes along
with tons of articles about how it's going to displace the current one in only
2 years. (RRAM has been one of "the new ones" for years.)

I'm not saying it won't happen, but on the journey from idea to millions of
units, a test chip is just the beginning, and in the meantime, NAND is moving.

Look at how slowly NAND has replaced rotating magnetic storage: it's been
around since the 80's. Decades of iteration have brought it to a place where
it's compelling for non-niche use cases.

------
mdaniel
How appropriate that this article and the following comic come out on the same
day:

[http://thedoghousediaries.com/5275](http://thedoghousediaries.com/5275)
(Amazing Scientific Breakthroughs)

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nshepperd
It's nice to see memristors bearing fruit (or about to soon) finally.

------
contingencies
Sad to think of the implications for the NSA.

