A Magnetic Memory Alternative to Hard Disk 258
Dr Occult writes "Finally, a magnetic memory chip has been manufactured in volume and released by the U.S. company Freescale. Christened MRAM (magnetoresistive random-access memory),this chip will hold information even after power has been switched off. From the BBC news article: 'Unlike flash memory, which also can keep data without power, Mram has faster read and write speeds and does not degrade over time,' and 'MRAM chips could one day be used in PCs to store an operating system, allowing computers to start up faster when switched on.'"
Freescale's PR (Score:5, Informative)
Price? (Score:4, Informative)
http://online.wsj.com/public/article/SB1152491713
Re:NOT a hard drive alternative (Score:5, Informative)
plans to shrink their new chips (29nm) under the
scales of the future standard 6T-SRAMs (still 45nm).
http://www.heise.de/newsticker/meldung/75243 [heise.de]
Re:When? (Score:2, Informative)
Re:more vaporware (Score:4, Informative)
Old news (Score:5, Informative)
That said, MRAM ain't a HD replacement yet. No one outside the aerospace industry is using it for storage right now that I'm aware of, and even if someone was, making a large enough FRAM based drive with 4Mb chips is HARD. 2 chips for every MB. 2048 chips for every GB. a 500GB FRAM disk would require 1,024,000 of these chips, requiring nearly 2,500 sqft of PCB space, and more power than a pile of overclocked P4s (~9mA * 3.3V * 1,024,000 chips = 30.4128kW at IDLE). Even if someone could build that, it'd be farking huge, run inconcievably hot, be incredibly power hungry, and sell for an obscenely expensive price, even for the most extr33m gadget hunters.
Wait for 32 and 64Mb chips. Then we'll talk.
Right now I'm too busy working with a serial FRAM from Ramtron [rantron.com] to write more.
Re:more vaporware (Score:3, Informative)
Re:more vaporware (Score:3, Informative)
Now, apparently. That's what this story is about. Here's [freescale.com] a link to the actual chip's spec sheet. Here's [freescale.com] a link to the chip's page on Freescale, where you can order it for $25/chip in 1000 unit quantities.
It's not in any consumer products yet, no, but it is available to purchase, which means it isn't vaporware.
512kB chip: $25 (Score:3, Informative)
"The MR2A16A is a 4,194,304-bit magnetoresistive random access memory (MRAM) device organized as 262,144 words of 16 bits"
Not ready for PC time yet.
Re:Old news (Score:1, Informative)
Re:Price? (Score:4, Informative)
At $25 in quantity for a 4-Mbit chip, it's about a factor of 5 higher than conventional SRAM. I'd guess that a factor of 5 in cost reduction isn't crazy to expect.
Too bad this chip didn't come out say, five to ten years ago - otherwise you likely would've been seeing it in video game cartridges for a while now.
Article misses the point almost completely... (Score:5, Informative)
- as fast as SRAM (i.e. cache in your processor)
- as small (i.e. as hight density) as DRAM; single MRAM memory cell is two magnets instead of two conductors of capacitor in DRAM, but the (theoretical) size is of the same order of magnitude
- non-volatile like Flash, but with random access and orders of magnitude faster, w/o "write penalty" and w/o erase/write cycles limit
- much less energy-hungry than SRAM, DRAM and Flash while working; when not working it can keep information at least as well as Flash
It's in development since the eighties and it will take time before we "get there" but it is possible, that one day MRAM could replace cache, main memory and memory cards in our computers.When? I have no idea, but AFAIR transistors didn't get from prototype to 65nm in a decade. Hopefully engineergs and managers in some semiconductor companies have longer attention span than an avarage slashdot reader.
Robert
Still pretty small (Score:3, Informative)
Here's the datasheet link: http://www.freescale.com/files/microcontrollers/do c/data_sheet/MR2A16A.pdf [freescale.com]
Re:Vaporware (Score:3, Informative)
The problems MRAM could address are very real, and people have been working on using MRAM/GMR-based memory for a long time for that very reason.
Re:Vaporware (Score:3, Informative)
so we're looking at 'about' 3 inches for 16meg (in this case)
Re:It doesn't quite seem to be (Re:) more vaporwar (Score:3, Informative)
Right now, they aren't. At that price point, they're competing with battery-backed SRAM (very nicely for the integrated stuff, and it depends on the product for the battery + battery monitor chip + SRAM solution).
Short primer on different memory technologies: SRAM is very fast, very low power, easy to interface, but it needs a battery for data integrity. DRAM is very cheap, but higher power, much harder to interface, and needs not only a battery but a controller for data integrity. EEPROM is everything SRAM is, but nonvolatile but is expensive, and writing requires awkward voltages, can't be done bytewise, and is slow anyway. Flash is similar to EEPROM, but beats it because it's cheaper, doesn't require weird voltages, but writing is still awkward.
The only downside to MRAM currently is its cost - fast and easy reads, fast and easy writes, nothing required to maintain it, and low power to boot. If this becomes available at distributors within a factor of 2 of that $25 price point, there's literally no point to integrated battery-backed SRAM chips anymore. If the price drops by a factor of 2 or so, there's no point to battery-backed SRAM at all.
As the price drops, though, MRAM has the potention to challenge all of those technologies above, as well as hard drives, much like flash is starting to do now.
Re:I bet it's hard to make it very small (Score:3, Informative)
Oops -- slaughtered that one, didn't I? It's been too long since I looked at the equations. Straightfoward Ampere's Law: the decrease is linear, not with the square of the distance.
Still, the decrease is significant enough, and the resistance to switching state high enough, that you don't generally have to worry about write lines inadvertently flipping more than one bit.
Re:NOT a hard drive alternative (Score:4, Informative)
Bzzzzt. Wrong. Thank you for playing.
OK. You are half-right. It would be expensive to crate an "MRAM hard drive." So, getting 20 gigs of MRAM would cost a small fortune. But this is NOT a "pump-n-dump." This is really cool stuff. I can easily imagine some embedded systems that could really use this stuff. This is non-volatile system memory. The problem with FLASH and EEPROM memory is that the cells wear out after a lot of writing (somewhere in the neighborhood of 10,000 to 1,000,000 write cycles will give you trouble). For some applications, this is not enough, so you have to resort to battery-backed SRAM. Now there is at least another option.
Although, really, this seems to solve the exact same problem as Phase-Change RAM [wikipedia.org].
Re:Is bootup time really that big of an issue? (Score:3, Informative)
35 ns cycle time for read or write (about 28.57 MHz), read modes 50 ma to 80 ma max, write modes 105 ma to 155 ma max, 9 ma to 12 ma max for stanndby (no pins changing state) and 18 ma to 28 ma with pins flying but no selection enabled for the chip. This is with a 4 mbit chip organized as either 8- or 16-bit. Couldn't find a spec for "the like", you'll have to be more specific. :-)
Those specs were abstracted from the PDF data sheet easily found at on this page. [freescale.com]
Re:Old news (Score:3, Informative)
And remember, my numbers were only for a 500GB x 1 byte array. That's horribly inefficient. If they can bump the width and depth of the array up, then we can talk. Let's hope they scale it fast and well.
Re:Back to the past.... (Score:5, Informative)
Reading MRAM is simpler than core memory becasue core memory had no read operation--it had "flip to zero" and "flip to one" and a "sense" line--the sense line would emit a pulse if a core element changed state. To read core memory, you had to do a "flip to zero" and watch the sense line--if it pulsed then a one was in the cell and you had to do a "flip to one" to restore it. If there was no pulse then it was already zero. With MRAM reading simply involves measuring the resistance of the insulating layer of a memory cell (the insulating material has the property where resistance increases as the magnetic field passing through it increases). IIRC there is nothing preventing parallel reads either. MRAMs are also much denser--megabits can fit in 0.25 cm^2
The "MRAM hard drive" thing may be hyperbole right now, but it looks like development of MRAM rechnology is significantly outpacing Moores Law. MRAM is also potentially as fast as SRAM and as dense as SDRAM--without the need for refresh circuitry so designs can be greatly simplified. Further downsizing could make it a good flash replacement. The biggest hurdle could be reduction...
Comment removed (Score:5, Informative)
Re:NOT a hard drive alternative (Score:3, Informative)
The fact that you would claim this gig crap proves that you don't have any idea of the issues involved here. Are you a troll, or just posting as AC so that no one calls you on your shit?
If you just replace your main memory with MRAM, then you can hibernate without writing out the contents of memory to disk. Think of it as a suspend-to-ram mode on steroids. Because the memory is not cleared, you can just restore processor state, pick up from where you were, reinitialize drivers, and move on with life. Just like coming back from hibernation mode.
This technology also opens up the possibility to use hard power switches on more systems, or low-power electronically switched relays. You don't need to maintain power to the device and run the power supply just so you can keep one memory chip going to retain settings.
Unfortunately (Score:4, Informative)
Re:I was alive in the 1980s (Score:3, Informative)
Magnetic bubbles did exist and were sold and used in computers. But at the time their was no niche for them like their is flashram. bubbles were faster than disks but more expensive and slower than ram but cheaper. Thus they got caught in a squeeze play. Although they consumed no current when off they were not particularly low power devices so they were not suited for battery powered devices. It's the latter that allows flashram to get a commerical foothold around which it has matured.
Mram is supposedly going to be faster then ram and consume less power. So it too may have a niche that eluded bubbles. it's main competitor is not flash or disk but ram I think.
Re:NOT a hard drive alternative (Score:1, Informative)
Industrial Compact Flash is >2,000,000 read/write cycles. And some advertise 3,000,000 cycles. http://www.psism.com/industrialcf.htm#industrialC
Re:Flash FS. Hm. How 'bout something actually used (Score:4, Informative)
A decent flash disk will have write-spreading as a layer on top of the filesystem, so it will remap sectors on the fly to avoid wearout.
Re:Found the datasheet... (Score:3, Informative)