3D XPoint is a non-volatile memory (NVM) technology by Intel and Micron Technology. Announced in July 2015, it is available on the open market under brand names Optane (Intel) and subsequently QuantX (Micron) since April 2017. The initial prices of it are less than dynamic random-access memory (DRAM) but more than flash memory. In conjunction with a stackable cross-gridded data access array, bit storage is based on a change of bulk resistance.
The makers started developing 3D XPoint in 2012. Intel and Micron had joined hands previously to develop other non-volatile phase-change memory (PCM) technologies. According to Micron, 3D XPoint architecture differs from previous offerings of PCM and uses chalcogenide materials for both selector and storage parts of the memory cell that are faster and more stable than traditional PCM materials like GST (Germanium-Antimony-Tellurium). However, it is today thought as a subset of ReRAM (Resistive Random Access Memory).
Stated to use electrical resistance and to be bit addressable, 3D XPoint developers indicate that it is based on changes in resistance of the bulk material. As per Intel, it does not use a phase-change or memristor technology, although this is disputed by independent reviewers. No other supplier had developed a working resistive RAM or phase-change memory technology that was sampling and matched 3D XPoint’s performance and endurance. Intel announced the Optane brand for storage products based on 3D XPoint technology in mid-2015.