The Samsung PM981 is an OEM SSD featuring a newer generation of controller and flash than the current retail 960 EVO, resulting in improved performance and hopefully lower prices. The PM981 will be Samsung’s mainstream NVMe drive for OEMs in 2018 and this is a preview of their next retail NVMe SSDs.

Source: AnandTech – The Samsung PM981 SSD Review (512GB, 1TB): Next Generation Controller And 3D NAND