WD finally entered the PCIe 4.0 NVMe SSD market, and released their first Gen4 SSD the WD_Black SN850 NVMe SSD. The SN850 challenges Samsungs, also latest, 980 Pro Gen4 SSD. Unlike the early Gen4 SSDs, the SN850 offers much faster sequential speeds of up to 7,000MB/s read and up to 5,300MB/s sequential write.