Scientists show that Phase-Change Memory technology can be significantly faster and durable than existing flash computer memory.
The speed of current computing systems is dependant on flash memory efficiency. Although sustainable for now, it does have some setbacks.
The incessant information exchange between a Random Access Memory (RAM) circuit and the hard drive results in time delays. This significantly affects the machine’s speed and durability.
Another major concern with the traditional RAM is their miniaturization limits.
To counteract this, scientists are working to cut away from Von Neumann architecture. This is a structure that has been at the core of computing since the 1950s.
One of the potential memory technologies in this regard is Phase-Change Memory.
What is it, and how does it compare to flash memory in terms of speed and durability?
Phase-Change Memory: Perfect RAM
A form of Random Access Memory (RAM), Phase-Change Memory (PCM) stores data by changing the state of the “bit” matter on a microscopic scale between liquid, glass, and crystal states.
PCM technology, with its cheap “non-volatile” storage at unprecedented speed, density, and volume, is poised to be a viable solution to future computing systems.
In addition to high-speed, PCM technology allows for a much larger memory lifespan than conventional flash memory.
Called “Perfect RAM“, PCMs overwrite information without having to erase it first. This is different to flash memory and allows PCMs to operate faster and last longer.
But exactly how fast PCM can be?
An international team of molecular and materials scientists from the U.S. and Germany has gathered to answer this question.
A Thousandfold Faster
Researchers from Arizona State University and three German universities (RWTH Aachen, TUM, and Saarland) published a study where they deemed PCMs to be a superior alternative to today’s flash memory devices.
The team worked on a PCM material made of germanium, antimony and tellurium.
Using quasi-elastic neutron scattering (QENS), they investigated the “microscopic dynamics in the liquid state” of this semimetallic alloy.
The QENS analysis showed that the PCM material alters between glass and crystal states, or vice versa, via the liquid intermediate “on the time scale of a thousandth of a millionth of a second” just by controlling heat or light pulses.
Researchers concluded that phase-change memories can work a thousand times faster than their flash counterparts, “while being significantly more durable with respect to the number of daily read-writes”.
Shuai Wei, a physicist at RWTH Aachen and co-author of the study, explains:
”The amorphous phases of this kind of material can be regarded as ‘semi-metallic glasses’. Contrary to the strategy in the research field of “metallic glasses,” where people have made efforts for decades to slow down the crystallization in order to obtain the bulk glass, here we want those semi-metallic glasses to crystallize as fast as possible in the liquid, but to stay as stable as possible when in the glass state. I think now we have a promising new understanding of how this is achieved in the PCMs under study.”
Researchers here show that PCM technology boasts greater speed and durability. However, there’s still some work to do to shed light on the potential of PCM devices to meet large-scale needs, compared to flash memory.