Ultrastar DC SN640 NVMe SSD. The Ultrastar DC SN640 Solid State Drives usher in a new era of flash storage, bringing together the industry’s best combination of performance, capacity, endurance, and reliability, while using the most cost-effective flash available. This combination makes Ultrastar DC SN640 SSDs the ideal solution for a wide variety of enterprise applications, including the custom-built hyper-scale architectures many organizations are developing on their own by combining best-in-class hardware and software.