3D Xpoint has been commercially available for years under the Optane brand name. It's much more expensive than NAND (16 and 32GB NVMe drives available for ~$2/G

3D Xpoint has been commercially available for years under the Optane brand name. It's much more expensive than NAND (16 and 32GB NVMe drives available for ~$2/GB) but a smallish amount in the Xbox acting as some sort of cache seems at least semi-plausible and would fit with the "next generation SSD" and "virtual RAM" statements.