Numonyx announces phase-change memory for consumer devices

Computerworld - Numonyx B.V. introduced two phase-change memory (PCM) products aimed at replacing DRAM and NOR memory used in PCs, wireless devices or other consumer devices with firmware or embedded applications.

The new embedded memory chips have many of the same attributes as flash memory, random access memory (RAM) and electrically erasable programmable read-only memory (EEPROM), according to Numonyx. PCM also has far greater endurance for data writes and vastly better performance. However, it's also much pricier than other floating-gate memory chips, such as DRAM and NAND flash.

Numonyx did not release a suggested retail price, saying only that their products will have a premium over existing memory chips until volume ramps up.

PCM, which is also known as phase-change random access memory (PRAM) is a form of nonvolatile memory based on using electrical charges to change areas on a glassy material from crystalline to random. PCM promises eventually to be faster and cheaper than other forms of memory, and to consume less power. For now, it remains more costly because production has not reached economies of scale.

Numonyx's new Omneo P5Q PCM chip has the newer and more popular serial peripheral interface, while its Omneo P8P PCM product uses the older, but more established, parallel NOR interface. Both products have 128Mbit capacities. The P5Q PCM chip comes in single, dual, and quad I/O serial interface.

According to Clifford Smith, manager for emerging technologies at Numonyx, the new PCM products offer up to 300 times faster write speeds than NAND flash or NOR and 10 times more write endurance than today's flash memory.

"Serial interface is really the growing market for NOR," said Jim Handy, an analyst with Objective Analysis in Los Gatos, Calif. "NOR is used anywhere there's a microcontroller. I once estimated that a PC typically has between half a dozen [to] a dozen NOR chips inside. An iPhone has something like three NOR chips in it. They're just all over the place."

As a replacement for DRAM, PCM addresses not only the write endurance issues, but also the use of power. In order to store data, DRAM requires continuous power. But PCM is non-volatile, like flash memory, meaning it continues to store data even when a device is turned off.

PCM lasts longer because, unlike flash memory, it doesn't have to perform an erase function before a write. It simply overwrites cells where bits of data already exist. Numonyx calls that function "byte alterability." Because flash memory has a limited number of write/erase cycles, it can wear out faster.

The Numonyx chips boast one million write cycles, 10 times more than the high-end, single-level cell (SLC) NAND flash memory used in enterprise-class solid-state drives (SSDs).