Everspin today announced it's shipping samples of the industry's most dense magnetoresistive RAM (MRAM), which can replace standard DRAM for write caching operations as it's 10,000 times faster than NAND flash.
The non-volatile memory, which Everspin calls spin-torque MRAM (ST-MRAM), is the company's third generation of MRAM and it is aimed at replacing persistent DRAM on servers and storage arrays.
Spin torque is simply a method of changing data bits from ones to zeros or vice versa by using a tiny bit of voltage to flip them up or down versus left or right, as is done with conventional MRAM; it also offers greater memory densities and requires 40% to 50% less power. The ST-MRAM operates on the DDR3/DDR4 DRAM memory interface.
Everspin shipped its first ST-MRAM chip in 2012. That memory was 500 times faster than NAND flash, but held only 64Mbit of data. To date, the company has shipped more than 60 million MRAM discrete and embedded products into data centers, it stated in a news release.
Everspin is currently sampling a 256Mbit chip, but it also plans ship a 1Gbit product based on its proprietary perpendicular magnetic tunnel junction later this year.
"Everspin's MRAM has demonstrated interface speeds comparable to DRAM; the new 256Mb and 1Gb ST-MRAM products will continue this performance with DDR3 and DDR4 interfaces, respectively," the company said in its news release.
While vastly faster than NAND flash memory, ST-MRAM is not intended to replace NAND flash, according to Everspin CEO Phill LoPresti. The non-volatile memory is being marketed as a replacement for DRAM using in write caching operations where super capacitors are needed to ensure data is not lost when power goes out.
ST-MRAM would be able to replace write cache, which is typically made up by a small volume of very expensive high-performance SRAM, a small amount of NAND flash and a super capacitor that provides enough power to keep SRAM online long enough to write to the non-volatile memory.
In essence, ST-MRAM would act as the tirst tier of storage in a storage array or server, protecting data not yet stored on the mass storage device, such as NAND flash or hard disk.
"MRAM instantly secures data in flight without the concern of data corruption due to the unreliability of power sources, as well as the slower write performance of NAND and other persistent memories," Everspin stated.