Toshiba reveals spin transfer RAM
Beats SRAM power consumption by 90% thanks to perpendicular magnetization
Toshiba has revealed it has developed a model for transfer torque magnetoresistive random access memory (STT-MRAM) and has claimed it has, for the first time, beaten the power requirements of static random-access memory (SRAM).
STT-MRAM has been on memory-makers' radar for a few years, and works by imparting spin – the angular momentum possessed by an electron – to a storage medium. Controlling spin, rather than the state of a transistor, becomes the way to store data. It's then possible to read the spin, which can go either left or right and therefore represent zero or one. STT-RAM is non-volatile.
Toshiba's calling its innovation in this area “perpendicular magnetization” and says, in a sketchy announcement, that the technique sees “Magnetization perpendicular to the magnetic layer. This can be reversed at a lower energy level than in-plane magnetization, making it possible to program data at a lower current and fabricate smaller transistors.”
Just how small, you ask? Below 30nm, Toshiba says, adding that its new kit offers “no passes for current to leak into cuts leak current to zero in both operation and standby without any specific power supply management.” The company also says STT-MRAM is jolly fast, and uses 90 per cent less electricity than SRAM.
As ever, there's no word on just when STT-MRAM might appear in a device, but it's worth noting that electron spin has featured in these pages more than once of late, with IBM investigating it for use in mass storage and RAM.
All of which may keep the term “spinning rust” alive for a while yet, never mind the growing prevalence of solid state storage. ®