https://www.theregister.co.uk/2018/07/26/david_kanter_optane_dimms/

Analysis Semiconductor analyst David Kanter has identified six areas of ignorance about Intel's Optane DIMMs where clarity will dictate whether they become popular or not.

Optane is a brand name for Intel's 3D XPoint memory, the storage technology that can be found in its P4800X series SSDs. The name has been slapped on Intel's forthcoming byte-addressable persistent memory DIMMs, which have a DDR4 bus interface that's faster than the P4800X's PCIe 3.0 x4 interface. They are sampling now in 128GB, 256GB, and 512GB capacities.