(3D Cross Point) A non-volatile phase change memory and storage technology from Intel and Micron. Optane is Intel's brand for 3D XPoint, while Micron uses the QuantX moniker. Less expensive and denser than dynamic RAM (DRAM), XPoint is more costly than NAND flash but is considerably faster while using less power.
Both Memory and Storage
3D XPoint has unique attributes. Like all RAM chips (DRAM and SRAM), it is byte addressable and can thus be used as main memory or as a secondary RAM bank. Because it is non-volatile, it can also replace an SSD or hard drive or be used in conjunction with them.
XPoint is expected to be available in 256GB and 512GB modules compared to DDR4 capacities, which typically max out at 64GB. See byte addressable
Cross Point Structure
Voltage applied to the top and bottom wire of the selector causes the cell to be read or written, and transistors are not required at each cell like they are with DRAM. Unlike flash memory that has a limited life span, XPoint is not affected by the number of write cycles. (Image courtesy of Intel.)
Addressable Volatile Speed
SRAM Yes No Fastest
DRAM Yes No Faster
XPoint Yes Yes Fast
NAND No Yes Slow