Everspin Briefing Note
The concept of persistent memory, also known as non-volatile DRAM, has been with us for a while. However, the idea of RAM that never loses data even during an unexpected power loss is IT nirvana. Today’s semiconductor storage technology exists primarily because DRAM does not retain data if it loses power.
With a persistent memory tier servers would “sleep” instead of crashing and corrupting data. Using persistent memory as a storage tier with the attributes of DRAM-like high performance and high endurance with no write penalty creates a whole new tier of storage. A true persistent memory also eliminates the need for capacitors and/or batteries to keep DRAM charged long enough until power is restored.
While persistent memory does indeed sound like nirvana, the technologies are not without their challenges. The first step in the process is to get a product off the design table and into production. These initial production runs are often very small and produce a sample that potential vendors can test. At the same time the memory manufacturer needs to keep shrinking the lithography of the chip so densities can increase and costs can come down.
There are several persistent memory technologies competing to become the next memory technology. Everspin designs MRAM-based persistent memory. MRAM is a method of storing data using magnetic polarization or electron spin instead of the electrical charges used by DRAM (dynamic random access memory). It has similar read, write and endurance characteristics to traditional DRAM, but it is, of course, persistent.
Everspin is now shipping the world’s first product using perpendicular magnetic tunnel junction (pMTJ)-based ST-MRAM to customers. This enables Everspin to leapfrog the competition in terms of density. It can now demonstrate an all ST MRAM SSD with 2 each of 512 MB SODIMM modules to sustain over 1.5M IOPS 4KB random writes on a single PCIe NVMe board.
When comparing to traditional flash storage the Everspin Technology 256MB ST MRAM is able to support over 100,000 times faster write speeds than today’s flash devices while offering significantly higher endurance. The 512MB ST MRAM module is DDR3 interface compatible, which should allow server vendors to integrate the technology quickly.
Everspin seems to be out in front in persistent technology. The company shipped over 60 million discrete MRAM components. The use cases for persistent memory are numerous, ranging from storage systems, to in-memory databases to Internet of Things (IoT) devices. Storage systems vendors and server manufacturers in particular need to pay attention and start to integrate the technology. Early movers integrating the technology will have a distinct advantage over their competition.