A knowledge ark, the Arch project

Read an article last week on the Arch Mission Foundation project, which is a non-profit, organization that intends “to continuously preserve and disseminate human knowledge throughout time and space”.

The way I read this is they want to capture, preserve  and replicate all mankind’s knowledge onto (semi-)permanent media and store this information  at various locations around the globe and wherever we may go.

Interesting way to go about doing this. There are plenty of questions and considerations to capturing all of mankind’s knowledge.

Google’s way

 Google has electronically scanned every book in a number of library partners to help provide a searchable database of literature, check out the Google Books Library Project.

There’s over 40 library partners around the globe and the intent of the project was to digitize their collections. The library partners can then provide access to their digital copies. Google will provide full access to books in the public domain and will provide search results for all the rest, with pointers as to where the books can be found in libraries, purchased and otherwise obtained.

Google Books can be searched at Google Books. Last I heard they had digitized over 30M books from their library partners, which is pretty impressive since the Library of Congress has around 37M books. Google Books is starting to scan magazines as well.

Arch’s way

The intent is to create Arch’s (pronounced Ark’s) that can last billions of years. The organization is funding R&D into long lived storage technologies.

Some of these technologies include:

  • 5D laser optical data storage in quartz, I wrote about this before (see my 5D storage … post). Essentially, they are able to record two-tone scans of documents in transparent quartz that can last eons. Data is recorded in 5 dimensions, size of dot, polarity of dot  and 3 layers of dot locations through the media. 5D media lasts for 1000s of years.
  • Nickel ion-beam atomic scale storage, couldn’t find much on this online but we suppose this technology uses ion-beams to etch a nickel surface with nano-scale information.
  • Molecular storage on DNA molecules, I wrote about this before as well (see my DNA as storage… post) but there’s been plenty of research on this more recently. A group from Padua, IT  shows the way forward to use bacteria as a read/write head for DNA storage and there are claims that a gram of DNA could hold a ZB (zettabyte, 10**21 bytes) of data. For some reason Microsoft has been very active in researching this technology and plan to add it to Azure someday.
  • Durable space based flash drives, couldn’t find anything on this technology but assume this is some variant of NAND storage optimized for long duration.  Current NAND loses charge over time. Alternatively, this could be a version of other NVM storage, such as, MRAM, 3DX, ReRAM, Graphene Flash, and  Memristor all of which I have written about
  • Long duration DVD technology, this is sort of old school but there exists archive class WORM DVDs out and available on the market today, (see my post on M[illeniata]-Disc…).
  • Quantum information storage, current quantum memory lifetimes don’t much over exceed 180 seconds, but this is storage not memory. Couldn’t find much else on this, but it might be referring to permanent data storage with light.
M-Disc (c) 2011 Millenniata (from their website)
M-Disc (c) 2011 Millenniata (from their website)

They seem technology agnostic but want something that will last forever.

But what knowledge do they plan to store

In Arch’s FAQ they talk about open data sets like Wikipedia and the Internet Archive. But they have an interesting perspective on which knowledge to save. From an advanced future civilization perspective, they are probably not as interested in our science and technology but rather more interested in our history, art and culture.

They believe that science and technology should be roughly the same in every advanced civilization. But history, art and culture are going to be vastly different across different civilizations. As such, history, art and culture are uniquely valuable to some future version of ourselves or any other advanced scientific civilization.

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Arch intends to have multiple libraries positioned on the Earth, on the Moon and Mars over time. And they are actively looking for donations and participation (see link above).

Although, I agree that culture, art and history will be most beneficial to any advanced civilization. But there’s always a small but distinct probability that we may not continue to exist as an advanced scientific civilization. In that case, I would think, science and technology would also be needed to boot strap civilization.

To the Wikipedia, I would add GitHub, probably Google Books, and PLOS as well as any other publicly available scientific or humanities journals that available.

And don’t get me started on what format to record the data with. Needless to say, out-dated formats are going to be a major concern for anything but a 2D scan of information after about ten years or so.

In any case, humanity and universanity needs something like this.

Photo Credit(s): The Arch Mission Foundation web page

Google Books Library search on Republic results

“Five dimensional glass disks …” from The Verge

M-disk web page

ReRAM to the rescue

I was at the Solid State Storage Symposium a couple of weeks ago where Robin Harris (StorageMojo) gave the keynote presentation. In his talk, Robin mentioned a new technology on the horizon which holds the promise of replacing DRAM, SRAM and NAND called resistive random access memory (ReRAM or RRAM).

If so, ReRAM will enter the technological race pitting MRAM, Graphene Flash, PCM and racetrack memory as followons for NAND technology.  But none of these have any intention of replacing DRAM.

Problems with NAND

There are a few problems with NAND today but the main problem that affects future NAND technologies is as devices shrink they lose endurance. For instance, today’s SLC NAND technology has an endurance of ~100K P/E (program/erase) cycles, MLC NAND can endure around 5000 P/E cycles and eMLC somewhere in between.  Newly emerging TLC (three bits/cell) has less even endurance than MLC.

But that’s all at 30nm or larger.  The belief is that as NAND feature size shrinks below 20nm its endurance will get much worse, perhaps orders of magnitude worse.

While MLC may be ok for enterprise storage today, much less than 5000 P/E cycles could become a problem and would require ever more sophistication in order to work around these limitation.    Which is why most enterprise class, MLC NAND based storage uses specialized algorithms and NAND controller functionality to support storage reliability and durability.

ReRAM solves NAND, DRAM and NvRAM problems.

Enter ReRAM, it has the potential to be faster than PCM-RAM, has smaller features than MRAM which means more bits per square inch and uses lower voltage than racetrack memory and NAND.    The other nice thing about ReRAM is that it seems readily scaleable to below 30nm feature geometries.  Also as it’s a static memory it doesn’t have to be refreshed like DRAM and thus uses less power.

In addition, it appears that  ReRAM is much more flexible than NAND or DRAM which can be designed and/or tailored to support different memory requirements.   Thus, one ReRAM design can be focused on standard  DRAM applications while another ReRAM design can be targeted at mass storage or solid state drives (SSD).

On the negative side there are still some problems with ReRAM, namely the large “sneak parasitic current” [whatever that is] that impacts adjacent bit cells and drains power.  There are a few solutions to this problem but none yet completely satisfactory.

But it’s a ways out, isn’t it?

No it’s not. BBC and Tech-On reported that Panasonic will start sampling devices soon and plan to reach volume manufacturing next year.   Elpida-Sharp  and HP-Hynix are also at work on ReRAM (or memristor) devices and expect to ship sometime in 2013.  But for the moment it appears that Panasonic is ahead of the pack.

At first, these devices will likely emerge in low power applications but as vendors ramp up development and mass production it’s unclear where it will ultimately end up.

The allure of ReRAM technology is significant in that it holds out the promise of replacing both RAM and NAND used in consumer devices as well as IT equipment with the same single technology.  If you consider that the combined current market for DRAM and NAND is over $50B, people start to notice.

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Whether ReRAM will meet all of its objectives is yet TBD.  But we seldom see any one technology which has this high a potential.  The one remaining question is why everybody else isn’t going after ReRAM as well, like Samsung, Toshiba and Intel-Micron.

I have to thank StorageMojo and the Solid State Storage Symposium team for bringing ReRAM to my attention.

[Update] @storagezilla (Mark Twomey) said that “… Micron’s aquisition of Elpida gives them a play there.”

Wasn’t aware of that but yes they are definitely in the hunt now.

Comments?

Image: Memristor by Luke Kilpatrick

 

Graphene Flash Memory

Model of graphene structure by CORE-Materials (cc) (from Flickr)
Model of graphene structure by CORE-Materials (cc) (from Flickr)

I have been thinking about writing a post on “Is Flash Dead?” for a while now.  Well at least since talking with IBM research a couple of weeks ago on their new memory technologies that they have been working on.

But then this new Technology Review article came out  discussing recent research on Graphene Flash Memory.

Problems with NAND Flash

As we have discussed before, NAND flash memory has some serious limitations as it’s shrunk below 11nm or so. For instance, write endurance plummets, memory retention times are reduced and cell-to-cell interactions increase significantly.

These issues are not that much of a problem with today’s flash at 20nm or so. But to continue to follow Moore’s law and drop the price of NAND flash on a $/Gb basis, it will need to shrink below 16nm.  At that point or soon thereafter, current NAND flash technology will no longer be viable.

Other non-NAND based non-volatile memories

That’s why IBM and others are working on different types of non-volatile storage such as PCM (phase change memory), MRAM (magnetic RAM) , FeRAM (Ferroelectric RAM) and others.  All these have the potential to improve general reliability characteristics beyond where NAND Flash is today and where it will be tomorrow as chip geometries shrink even more.

IBM seems to be betting on MRAM or racetrack memory technology because it has near DRAM performance, extremely low power and can store far more data in the same amount of space. It sort of reminds me of delay line memory where bits were stored on a wire line and read out as they passed across a read/write circuit. Only in the case of racetrack memory, the delay line is etched in a silicon circuit indentation with the read/write head implemented at the bottom of the cleft.

Graphene as the solution

Then along comes Graphene based Flash Memory.  Graphene can apparently be used as a substitute for the storage layer in a flash memory cell.  According to the report, the graphene stores data using less power and with better stability over time.  Both crucial problems with NAND flash memory as it’s shrunk below today’s geometries.  The research is being done at UCLA and is supported by Samsung, a significant manufacturer of NAND flash memory today.

Current demonstration chips are much larger than would be useful.  However, given graphene’s material characteristics, the researchers believe there should be no problem scaling it down below where NAND Flash would start exhibiting problems.  The next iteration of research will be to see if their scaling assumptions can hold when device geometry is shrunk.

The other problem is getting graphene, a new material, into current chip production.  Current materials used in chip manufacturing lines are very tightly controlled and  building hybrid graphene devices to the same level of manufacturing tolerances and control will take some effort.

So don’t look for Graphene Flash Memory to show up anytime soon. But given that 16nm chip geometries are only a couple of years out and 11nm, a couple of years beyond that, it wouldn’t surprise me to see Graphene based Flash Memory introduced in about 4 years or so.  Then again, I am no materials expert, so don’t hold me to this timeline.

 

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Comments?

The future of data storage is MRAM

Core Memory by teclasorg
Core Memory by teclasorg

We have been discussing NAND technology for quite awhile now but this month I ran across an article in IEEE Spectrum titled “a SPIN to REMEMBER – Spintronic memories to revolutionize data storage“. The article discussed a form of magneto-resistive random access memory or MRAM that uses quantum mechanical spin effects or spintronics to record data. We have talked about MRAM technology before and progress has been made since then.

Many in the industry will recall that current GMR (Giant Magneto-resistance) heads and TMR (Tunnel magneto-resistance) next generation disk read heads already make use of spintronics to detect magnetized bit values in disk media. GMR heads detect bit values on media by changing its electrical resistance.

Spintronics however can also be used to record data as well as read it. These capabilities are being exploited in MRAM technology which uses a ferro-magnetic material to record data in magnetic spin alignment – spin UP, means 0; spin down, means 1 (or vice versa).

The technologists claim that when MRAM reaches its full potential it could conceivably replace DRAM, SRAM, NAND, and hard disk drives or all current electrical and magnetic data storage. Some of MRAM’s advantages include unlimited write passes, fast reads and writes and data non-volatilility.

MRAM reminds me of old fashioned magnetic core memory (in photo above) which used magnetic polarity to record non-volatile data bits. Core was a memory mainstay in the early years of computing before the advent of semi-conductor devices like DRAM.

Back to future – MRAM

However, the problems with MRAM today are that it is low-density, takes lots of power and is very expensive. But technologists are working on all these problems with the view that the future of data storage will be MRAM. In fact, researchers at the North Carolina State University (NCSU) Electrical Engineering department have been having some success with reducing power requirements and increasing density.

As for data density NCSU researchers now believe they can record data in cells approximating 20 nm across, better than current bit patterned media which is the next generation disk recording media. However reading data out of such a small cell will prove to be difficult and may require a separate read head on top of each cell. The fact that all of this is created with normal silicon fabrication methods make doing so at least feasible but the added chip costs may be hard to justify.

Regarding high power, their most recent design records data by electronically controlling the magnetism of a cell. They are using dilute magnetic semiconductor material doped with gallium maganese which can hold spin value alignment (see the article for more information). They are also using a semiconductor p-n junction on top of the MRAM cell. Apparently at the p-n junction they can control the magnetization of the MRAM cells by applying -5 volts or removing this. Today the magnetization is temporary but they are also working on solutions for this as well.

NCSU researchers would be the first to admit that none of this is ready for prime time and they have yet to demonstrate in the lab a MRAM memory device with 20nm cells, but the feeling is it’s all just a matter of time and lot’s of research.

Fortunately, NCSU has lots of help. It seems Freescale, Honeywell, IBM, Toshiba and Micron are also looking into MRAM technology and its applications.

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Let’s see, using electron spin alignment in a magnetic medium to record data bits, needs a read head to read out the spin values – couldn’t something like this be used in some sort of next generation disk drive that uses the ferromagnetic material as a recording medium. Hey, aren’t disks already using a ferromagnetic material for recording media? Could MRAM be fabricated/layed down as a form of magnetic disk media?? Maybe there’s life in disks yet….

What do you think?

What’s happening with MRAM?

16Mb MRAM chips from Everspin
16Mb MRAM chips from Everspin

At the recent Flash Memory Summit there were a few announcements that show continued development of MRAM technology which can substitute for NAND or DRAM, has unlimited write cycles and is magnetism based. My interest in MRAM stems from its potential use as a substitute storage technology for today’s SSDs that use SLC and MLC NAND flash memory with much more limited write cycles.

MRAM has the potential to replace NAND SSD technology because of the speed of write (current prototypes write at 400Mhz or a few nanoseconds) and with the potential to go up to 1Ghz. At 400Mhz, MRAM is already much much faster than today’s NAND. And with no write limits, MRAM technology should be very appealing to most SSD vendors.

The problem with MRAM

The only problem is that current MRAM chips use 150nm chip design technology whereas today’s NAND ICs use 32nm chip design technology. All this means that current MRAM chips hold about 1/1000th the memory capacity of today’s NAND chips (16Mb MRAM from Everspin vs 16Gb NAND from multiple vendors). MRAM has to get on the same (chip) design node as NAND to make a significant play for storage intensive applications.

It’s encouraging that somebody at least is starting to manufacture MRAM chips rather than just being lab prototypes with this technology. From my perspective, it can only get better from here…