IBM makes Phase-Change Memory breakthrough
Elena Vnorovscaia / Chişinău / Moldova.ORG / -- A University of California, San Diego team will next week demonstrate a phase-change memory solid state storage device that's thousands of times faster than a conventional hard drive.
IBM researchers have found a way of enabling phase-change memory to store data for longer, opening the way for low-cost, faster and more reliable memory applications.
Phase-change memory (PCM) is a non-volatile technology - it doesn't require power to store data - that has a far superior performance to flash. It's expected to find applications in consumer devices, including mobile phones and cloud storage, as well as high-performance applications such as enterprise data storage.
Phase-change memory (PCM) stores data in the crystal structure of a chalcogenide, a metal alloy. The PCM memory chips switch the alloy between a crystalline and amorphous state based on the application of heat through an electrical current. To read the data, the chips use a smaller current to determine which state the chalcogenide is in.
PCM can write and retrieve data 100 times faster than flash, enable high storage capacities and doesn't lose data when the power is turned off. Unlike flash, it's also very durable and can endure at least 10 million write cycles, compared to current enterprise-class flash at 30,000 cycles or consumer-class flash at 3,000 cycles.
It is also up to seven times faster than the best solid-state drives (SSDs).
The UC device, Moneta, uses Micron Technology's first-generation PCM chips and can read large sections of data at a maximum rate of 1.1 gigabytes per second and write data at up to 371 megabytes per second.
For smaller accesses, for example 512B, Moneta can read at 327 megabytes per second and write at 91 megabytes per second - between two and seven times faster than a state-of-the-art, flash-based SSD.
"Phase-change memory-based solid state storage devices will allow us to sift through all of this data, make sense of it, and extract useful information much faster," says Steven Swanson, professor of computer science and engineering. "It has the potential to be revolutionary."
But a major problem has been what's called short-term drift, which causes the stored resistance levels to shift over time, leading to read errors. Up to now, reliable retention of data has only been shown for single bit-per-cell PCM, and not in multi-bit PCM.
But the IBM researchers have been able to overcome this problem through a clever software trick that encodes the data in such a way that when it's read out, they can correct for drift-based errors.
Also Swanson says, that "We've found that you can build a much faster storage device, but in order to really make use of it, you have to change the software that manages it as well. Storage systems have evolved over the last 40 years to cater to disks, and disks are very, very slow".
Comments