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Phase Change Memory Points To Future of Storage
An anonymous reader writes
"A UC San Diego team is about to demonstrate a solid state storage device that it says provides performance thousands of times faster than a conventional hard drive and up to seven times faster than current state-of-the-art solid-state drives. The drive uses first-of-its-kind phase-change memory, which stores data in the crystal structure of a metal alloy called a chalcogenide. To store data, the PCM chips switch the alloy between a crystalline and amorphous state based on the application of heat through an electrical current. To read the data, the chips use a smaller current to determine which state the chalcogenide is in."
I suppose this will allow Micron to announce that skunkworks project that's been floating around since 2009 or so...
I read something similar about HP memristors
My very first reaction was to think of Asimov's Foundation trilogy and the fact the the Galactic Library was stored as nicked quanta in a paperweight on the Librarian's desk. The Barbarians allowed him to take his personal belongings with him before they destroyed the Library Planet.
No longer will I need a huge magnet, now I just need a hair dryer!
But Seriously, wouldn't external heat sources pose a problem for such a technology? I don't want my drive erased next time my electricity goes out during the summer.
Where genius and insanity become confused true wisdom is found
Okay... atomic bombs are one thing, but now the aliens are really going to take notice. We're starting to use the same technology as them.
To store data, the PCM chips switch the alloy between a crystalline and amorphous state based on the application of heat through an electrical current.
That seems like probably not a very good idea, and I'm sure it will end up being one of the major hurdles to this technology really getting off the ground. What happens when the memory is heavily used (leading to buildups of heat in the memory that could cause unintentional bit changes)? Obviously the heat used to flip the bits must be dissipated very, very quickly, and that's a pretty challenging problem in its own right. Also, what happens to system temps when you use this memory? Many systems are already difficult to keep cooled, and adding another source of heat could be a particularly bad idea. Heck, what if the increase in system temps leads to memory faults? After looking over the Wiki, the last question seems unlikely to be a problem, but heating something to >600C seems like it could make it very hard to use this tech in heavy use situations.
Make that 8.8 gigabits per second compared to 6Gb/s hard drive. Doesn't sound revolutionary. There must be something in the other details that make this exciting.
skimmed some papers on PCM on the web, looks like their goals are to get the memory to 100 million writes and 10 years retention of data; very similar issues to flash, it seems
So, what's up with the name of the system, "moneta", is it what I think it is (a Russian word for 'coin'), or is there something else at play here? I am a bit confused, because in the article, (which I am sorry to admit I read), it mentioned a bunch of names, but none that were Russian sounding.
You can't handle the truth.
I actually skimmed the article and I didn't see any mention of data density. Anyone know how it compares?
Vote monkeys into Congress. They are cheaper and more trustworthy.
RAM is hot because the entire DIMM has to switch transistors to maintain the current state of memory. The heat in this instance would be involved in reading and writing only the portion in use at that moment. The circuits that handle the memory bus communication would be continuously active, so that might be a local problem area for the device. Does NVRAM get hot like RAM does? I don't have numbers but my understanding of the technologies suggest not.
what about power consumption? that's the real showstopper nowadays
Phase change memory tech is not new as most readers here will know. Nearly all the major semiconductor companies have worked on prototype versions of this tech. If companies like Samsung and Intel haven't succeeded in mass producing it yet, as a consumer I'd be more interested in knowing what sets this particular device apart from all the others that will make it more likely to reach the market for the masses. Cheaper to produce? Scales more easily? More energy efficient? More stable?
"The only normal people are the ones you don't know very well."
Is what is the number of cycles before a given bit can no longer be changed. Will this outlast the current SSD write cycle limitations that are getting smaller not longer with the ever shrinking die size thus resulting in having to have 2x or 4x the actual advertised RAM installed to meet ever increasing MTBF rates..
Beware the Lollipop of Mediocrity, Lick it once and you suck forever.
If it works as described with the PCB generating heat to change the substance from a crystal to a liquid, once that heat is removed via loss of power, all would change back to a crystal, and you would lose all your data. This may be fine for RAM, but not for storage.
We were all warned a long time ago that MS products sucked, remember the Magic 8 Ball said, "Outlook not so good"
A UC San Diego team is about to demonstrate a solid state storage device that it says provides performance thousands of times faster than a conventional hard drive and up to seven times faster than current state-of-the-art solid-state drives.
I don't know why, but the speed comparisons in the summary amuse me. "This is THOUSANDS of times faster than a conventional hard drive — absolutely phenomenal speed gains, faster than anything else ever seen in the conventional hard drive world , speeds which will blow your mind straight out of your skull with how much blindingly faster they are than conventional hard drives, literally THOUSANDS of times faster — and kinda sorta faster than solid-state drives."
Demanding constant attention will only lead to attention.
If it works as described with the PCB generating heat to change the substance from a crystal to a liquid, once that heat is removed via loss of power, all would change back to a crystal, and you would lose all your data. This may be fine for RAM, but not for storage.
Actually I think you'll find it's the same material and a similar principle to CD-RW disks. The difference is that in CD-RW they are heating it with a laser, and reading it back optically. In PC memory, they are probably heating it electrically, and they are using a change in resistance rather than a change in reflectivity to read it back.
I'm struggling to understand what these researchers have made, exactly. They certainly didn't invent phase-change memory, and the article states that this "Moneta" uses memory modules from Micron Technology. The wikipedia article mentions Samsung started shipping modules last year, ready for use in mobile applications. So clearly PCM has been available for some time. So perhaps Moneta is an actual device available for end users? That would be exciting!
So it's not ready then. I really cannot see what these guys have achieved.
"A week in the lab saves an hour in the library"
No. Power is needed for the phase change (flipping a bit). PCRAM is non-volatile - it does not require power to retain its state. That's the entire point...
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"switch the alloy between a crystalline and amorphous state"
Interesting, this is similar how cd/dvd-rw works, where they use a laser to do the state change.
It's not switching between solid and liquid. It's switching between crystaline and amorphous solid (stated in the first wikipedia intro, second link in the article). It takes a small amount of heat to make it switch between the two states, and they have different properties that can be measured, but both states are static in the absence of heat. What you described would make no sense at all, since if the PCB knows to provide heat to certain places then it already has external memory.
Of more interest is the security of the data stored in PCM. Can you erase it by putting it in a microwave? Leaving it in a hot car? Will it be easy to make a microwave beam/laser to erase parts of the drive from outside? The answer is probably no, but it will be very interesting to see the temperature specs on the resulting consumer products.
The pioneer in the technology was Sanford R. Ovshinsky who called the technology Ovonics and whose company Energy Conversion Devices has been in business for a long time. What is perhaps different about the new devices is improved speed and increased storage size.
I was interested in these materials in the 1970's as a substrate for a different kind of computer architecture. They were the starting point for my development of Brain Models that are not computers.
Bob Kovsky
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The drive uses first-of-its-kind phase-change memory,
In the 1960s Stanford R. Ovshinsky of Energy Conversion Devices first explored the properties of chalcogenide glasses as a potential memory technology. In 1969, Charles Sie published a dissertation,[1][2] at Iowa State University that both described and demonstrated the feasibility of a phase change memory device by integrating chalcogenide film with a diode array.
I understand everybody wants a crack at the recognition of being "the first", but c'mon, "first-of-its-kind"? Hardly.
Even in that second quote from wikipedia, It almost looks like friends of Ovshisky slip his moniker in ahead of somebody (Sie) who actually appears to have done all the heavy lifting."60's" versus "1969" with no refereed publication to support claims .....hmmm.....can we be a little more vague here.
OUM/OVM memory for storage applications. The IOPS should be quite nice once done properly.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Chalcogens (Oxygen, sulfur, selenium, etc.) are on the wrong end of the periodic table to be part of a metal alloy.
Maybe they meant "ceramic" instead?
idea, run everything in ram, archive image to even a slow hard drive .....
or have RAM able to be backed up with lithion, type batteries, such that you can shut everything else down, cpu, hard drives,,,vid card ...fans...and keep the image in ram, i'm thinking about something like that with one of these server boards with lots of ram slots, asus makes on, 128gig/256gig
even 8 gig RAM drive setup, even if i had to pull from a hd, and copy the 8gig back into memory every time, how long does that take?
on that asus board does anyone even make 16gig sticks?