IBM today announced a more efficient way to use phase-change memory, a breakthrough that could help transition electronic devices from standard RAM and flash to a much faster and more reliable type of storage. Phase-change memory, or PCM, is a type of non-volatile optical storage that works by manipulating the behavior of chalcogenide glass, which is how data is stored on rewriteable Blue-ray discs. A electrical current is applied to change PCM cells from an amorphous to crystalline structure, allowing you to store 0s and 1s in either state while the application of low voltage can read the data back.
The issue in the past has been PCM's limited capacity and high cost; you can typically only store one 1 bit per cell. That makes it less useful for main memory applications like laptop or mobile phone storage. Yet IBM researchers discovered how to store 3 bits per cell by tinkering with how the crystals react to high temperatures, which are required to tap into multiple states for PCM cells. The jump is significant 'because at this density, the cost of PCM will be significantly less than DRAM and closer to flash,' Haris Pozidis, IBM's manager of non-volatile memory research, wrote in a statement."