The Samsung 860 PRO was a solid-state drive in the 2.5" form factor, launched on January 23rd, 2018, that is no longer in production. It was available in capacities ranging from 256 GB to 4 TB. This page reports specifications for the 4 TB variant. With the rest of the system, the Samsung 860 PRO interfaces using a SATA 6 Gbps connection. The SSD controller is the MJX Maru (S4LR030) from Samsung, a DRAM cache chip is available. Samsung has installed 64-layer MLC NAND flash on the 860 PRO, the flash chips are made by Samsung. The 860 PRO is rated for sequential read speeds of up to 560 MB/s and 530 MB/s write; random IOPS reach up to 100K for reads and 90K for writes.
At its launch, the SSD was priced at 1900 USD. The warranty length is set to five years, which is an excellent warranty period. Samsung guarantees an endurance rating of 4800 TBW, a good value.