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Everspin Technologies, which produces high-density magneto-resistive random access memory for in-memory storage, has started sampling its 256-megabit chips to server, SSD and storage appliance vendors.
The MRAM 256-megabit (Mb) devices are manufactured with Everspin's proprietary perpendicular magnetic tunnel junction spin torque technology. The technique refers to a method of gating electrical current on each bit. Everspin stacks the chips in a vertical plane to increase cell density, allowing MRAM to function as persistent memory.
Everspin Technologies refers to its product as Spin Torque MRAM (ST-MRAM). The vendor said the previous ST-MRAM iteration, a 64 MB chip, is integrated in M.2 flash cards by Aupera, NVMe-compliant flash cards by Mangstor Inc., and SSDs by Buffalo Americas Inc.
Everspin ST-MRAM is intended for use as a high-performance write cache for applications with predictable latency. The DDR3-compatible device is engineered to protect in-flight data by buffering writes and signaling the host processor when the buffer can receive additional writes. Data subsequently gets written to flash from MRAM write buffers.
ST-MRAM an alternative to DRAM
Everspin Technologies launched in 2008 as a spinout of Freescale Semiconductor, which spun out of Motorola. The Chandler, Ariz.-based Everspin integrates magnetic storage during its CMOS manufacturing process. The storage uses a magnetic tunnel junction device to make calls directly to system memory.
LoPresti said IBM demonstrated Everspin Technologies' 256 Mb ST-MRAM technology, embedding it within DIMM devices running IBM's ConTutto configurable memory system. He said other OEMs plan to test Everspin's 256 Mb memory card.
"We created our family of DDR3-based spin-torque parts to address enterprise-class storage appliances, server-attached storage [with] RAID, and SSDs that get deployed in the enterprise," he said. "The big issue with all those technologies is that the write cache has to be protected if power fails, yet it has to be capable of accepting a high volume of writes with predictable latency.
"Our ST-MRAM operates at the same bandwidth speed as DRAM, but it's instantly nonvolatile. Data is protected as soon as you write it. You don't need firmware to monitor power or bulky super-capacitors taking up the entire back of the board."
Can Everspin Technologies lower manufacturing cost to spur adoption?
Alan Niebel, CEO at WebFeet Research Inc., said Everspin switched production to GlobalFoundries' 300-millimeter MRAM manufacturing to boost production levels and reliability of the ST-MRAM cards.
"They came out with 64 MB ST-MRAM two years ago, but it stalled because they couldn't manufacture it well. By going to 300-millimeter production, they have migrated from 90 nanometers down to 40 nanometers. The 256 Mb ST-MRAM gives them more ways to put it into an NVDIMM or other capabilities used in enterprise storage," Niebel said.
Being early in volume production gives Everspin Technologies time to reduce costs during manufacturing, said Jim Handy, a semiconductor industry analyst with Objective Analysis in Los Gatos, Calif.
"MRAM is still more expensive than established memory channel storage technologies, yet it behaves significantly better," Handy said. "The question is who is willing to pay extra for that behavior? Right now, that's a relatively small handful of applications. You're more likely to find their product in RAID cards or used by SAN makers to do journaling. That's an application that today is sometimes performed by battery backup [with] static RAM."
LoPresti said Everspin is testing a 1 GB ST-MRAM device slated for release later this year.
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