The Samsung PM981 is a solid-state drive in the M.2 2280 form factor, launched in August 2017. It is available in capacities ranging from 256 GB to 2 TB. This page reports specifications for the 256 GB variant. With the rest of the system, the Samsung PM981 interfaces using a PCI-Express 3.0 x4 connection. The SSD controller is the Phoenix (S4LR020) from Samsung, a DRAM cache chip is available. Samsung has installed 64-layer TLC NAND flash on the PM981, the flash chips are made by Samsung. To improve write speeds, a pseudo-SLC cache is used, so bursts of incoming writes are handled more quickly. The cache is sized at 25 GB, once it is full, writes complete at 600 MB/s. The PM981 is rated for sequential read speeds of up to 3,000 MB/s and 1,300 MB/s write; random IO reaches 130K IOPS for read and 310K for writes.
At its launch, the SSD was priced at 59 USD. The warranty length is set to three years, which is above average, but shorter than the five years offered by many other vendors. The TBW rating for the Samsung PM981 256 GB is unknown.