Numonyx, a joint venture between Intel and STMicroelectronics, has announced a possible breakthrough in phase change memory (PCM). PCM represents the likely next step in computer memory for a variety of reasons. The newest announcement reveals that the companies have successfully stacked several layers of PCM on top of each other. By stacking several layers together, future memory will be cheaper and more powerful than the current NAND flash based memory. PCM will be able to accomplish these improvements as it will require less voltage, meaning the transistors can be scaled down to 5nm. NAND flash limits transistors to 20nm, and smaller transistors means more memory in a smaller area.