Intel and Micron Technology have been working on a new-generation memory technology since about 2012. It's called 3D XPoint (not to be confused with 3D NAND), and it's absurdly fast. A good way to think of it is as a compromise between the speed of DRAM and the capacity of traditional flash storage. Unlike RAM, 3D XPoint is non-volatile (doesn't lose what it's storing when the power is off), and it's about four times denser. It's more expensive per gigabyte than NAND flash — the current technology inside SSDs — but it's faster in nearly every possible way, especially when it comes to latency and reading / writing small bits of data.
