NEC Develops World's Fastest MRAM

Gary writes to tell us that NEC has developed a new SRAM compatible MRAM. The new memory module is capable of speeds up to 250MHz, the world's fastest to date. "MRAM are expected to generate new value and applications for future electronic devices thanks to their nonvolatility, unlimited write endurance, high speed operation, and ability to cut memory power dissipation in half. For example, these features could enable instant start up of PCs and prevent drive recorders from losing data after a sudden break in power in the future. As substitutes for system LSI-embedded SRAM, MRAM can provide even more value as they are expected to enable extremely low power dissipation of system LSIs because they can sleep when they are not in use and wake up instantly."

MRAM is actually used

[Dwedit]

For small sizes (32KiB), MRAM already has a wide use in Game Boy Advance cartridges as a replacement for battery backed RAM.

WTF is MRAM?

[bobdotorg]

I was unfamiliar with it, so I looked it up:

Magnetoresistive Random Access Memory - two magnetic plates separated by an insulator. One plate has is a permanent magnet, the other holds the temporary charge.

Re:Not a replacement for SRAM... yet

[Kazymyr]

Replying to my own post - here's a brief paper explaining the technology (PDF warning):
http://www.freescale.com/files/microcontrollers/doc/brochure/BRMRAMTECHGUIDE.pdf [freescale.com]

Re:MRAM Solid State Hard Drives

[goofy183]

I'm nearly positive that the read/write cycle issues have long been moot. http://www.storagesearch.com/ssdmyths-endurance.html [storagesearch.com] I realize this is an industry sponsored site but even with taking very pessimistic views of their numbers a flash drive will last far longer than most disk based drives on the market will.

Alternate link

[flatulus]

The linked article seems to be Slashdotted. http://www.nec.co.jp/press/en/0711/3001.html/ [nec.co.jp] is NEC's own press release.

It's about the power, stupid.

[randyest]

Too bad the summary had to mention "instant-on PC" because most of the responses so far are about "No way" or "my kewl macbook does that already" and such. The biggest advantage of MRAM over SRAM/eDRAM is not that it retains data without power (though that's nice too), it's that MRAM about as fast as current eDRAM and half the power. And even zero power when not used (while retaining most recent data) is a bonus.

This is a huge plus for ASICs and other chips (ASSPs, COTS, etc.) that have a lot of memory on them (which is most of them.) It allows more memory on a chip without expensive packages/die sizes for thermal management or complex, time-consuming power management systems. LSI (large-scale integrated) circuits use a lot of memory, and power consumption is a huge problem, so cutting that in half will enable a lot of products to be made that wouldn't have been possible/affordable before, and a lot of other products will get to market faster.

MRAM has been around for a while, but the relatively slow speed made it unsuitable for most applications. Now it will be great enabling technology that will ripple through many products that use semiconductor devices.

Re:Could the reverse be done?

[addaon]

The battery-backed SRAM used in devices like game cartridges is medium-speed, very-low-power SRAM. It's pretty standard to see battery ratings of five years; twenty years is available pretty readily. With times like these, there's really no reason to have secondary persistent storage, especially since the energy for doing the dump (which you must reserve) is likely to be enough to power the SRAM for another couple years.

Re:Could the reverse be done?

[mzs]

Yeah we use a cap and coin cell combo here at work. The capacitor provides about a week's worth of time, then the battery can do years. The cap is also useful for replacing the battery.

Re:Nick of time for NEC

[networkBoy]

One benefit for Ovonics based tech (PCM) is that it is inherently radiation and magnetic field resistant. While I realize that the former of those applications is nominal, the latter is not. It's only downfall is thermal stability, the temperatures experienced in reflow are sufficient to erase the memory. While this is beneficial from a security aspect (strip line heater on top of your memory bank, hit the panic button and poof the memory is blank) it may not be in other industrial applications.

Any indications about mRAM's magnetic/EMP stability?
-nB

Re:Hooray!

[networkBoy]

System memory is currently running at 266-333MHz in the high end so this is a perfectly viable replacement in mid-range systems. Also for embedded systems where start-up time is more visible to the consumer than raw speed, again this is a viable replacement.

Remember DDR2 PC800 is 200MHz quad pumped not 800MHz.
-nB