MRAM (magnetoresistive random access memory) has taken a step closer to superseding flash memory, after scientists in Singapore said the technology could lead to longer-lasting and easier-to-manufacture components.
MRAM offers potentially much greater density and speed of operation than existing NAND memory, upon which flash storage is based. This is because MRAM works by flipping magnetic poles to indicate memory states.
MRAM operations require small voltages and offer extremely low latencies, in the order of nanoseconds for reads and writes compared to tens or hundreds of microseconds for NAND flash. MRAM reads and writes also use similar voltages, unlike NAND flash, which needs a relatively large “charge pump” to write to cells.
The advance made by the Singapore scientists is to theorise the manufacture of MRAM structures comprising multiple layers of around 20 nanometres. Currently, MRAM requires manufacture of films of around one nanometre in thickness, which is difficult and costly to make, and can only retain data for around one year.
The new structures will hold data for much longer and with higher densities than flash can allow. The Singapore team has applied for a US provisional patent and is seeking commercial partners to develop the technology.
National University of Singapore team leader, Yang Hyunsoo, said in a statement: "Storage space will increase, and memory will be so enhanced that there is no need to regularly hit the 'save' button as fresh data will stay intact, even in the case of a power failure. Devices and equipment can now have bigger memory with no loss for at least 20 years or probably more. Currently, pursued schemes with a very thin magnetic layer can only retain information for about a year."
MRAM is one of a number of potential candidates to replace NAND flash, which is likely to become increasingly unsuited to enterprise operations over the next few years.
That’s because NAND flash manufacturing processes are dictated by the mobile device market. This requires ever smaller chips and emphasises read over write operations, which means even more background operations must be carried out in software and wear compensated for by spare capacity to meet enterprise operational requirements.
MRAM is already in use in Dell and LSI RAID controllers as journal memory.
03 Jan 2014