This is an old article (circa 2014) but it had some interesting information I wasn't already familiar with:
"4DS has worked with the Institute of Microelectronics in Singapore since 2011 to develop a 16-kbit ReRAM prototype and memory controller based on its technology. The technology is described as offering low-power operation, high-speed switching and scalability below 10nm. In addition it can be implemented as a back-end process on top of standard CMOS"
