WD Ultrastar DC SN655 WUS5EA138ESP7E1 3.84 TB NVMe PCIe 4.0 Read-Intensive Enterprise SSD

Data strategy, not just data storage — the WD Ultrastar DC SN655 is engineered for the world’s most demanding data-center workloads. This 3.84 TB NVMe SSD delivers sustained read performance, low latency, and enterprise-grade reliability designed for cloud providers, hyperscale deployments, and server ecosystems that demand rapid access to large datasets. Built to power data-intensive applications, caching layers, and analytics pipelines, the SN655 combines ample capacity with predictable performance to accelerate services, reduce bottlenecks, and improve overall application responsiveness. As part of Western Digital’s Ultrastar line, it emphasizes quality, endurance, and streamlined management in dense, high-demand environments. With a PCIe Gen4 x4 interface and a U.3 15 mm internal form factor, this drive integrates into a wide range of backplanes and servers, enabling flexible deployment from modern data centers to enterprise storage arrays. Whether you’re optimizing read-heavy workloads like database read replicas, content delivery caches, or data warehouse accelerators, the SN655 is designed to maintain performance under sustained load while helping organizations lower total cost of ownership through efficient capacity utilization and scalable resilience.

• Massive 3.84 TB capacity tailored for read-intensive workloads, enabling large-scale databases, caching layers, analytics pipelines, and content delivery scenarios without frequent tiering or capacity fragmentation.
• PCIe 4.0 NVMe interface delivers broad bandwidth and low latency, translating into faster data access, higher IOPS, and smoother performance for parallel read-heavy tasks in multi-tenant cloud and on-prem environments.
• Enterprise-grade reliability and endurance engineered for continuous operation, helping data centers maintain consistent performance and data integrity across heavy read workloads and long service lifecycles.
• U.3 15 mm internal form factor provides flexible integration into diverse backplanes, servers, and storage enclosures, simplifying deployment in dense racks and scalable hyperscale infrastructure with standardized drive interfaces.
• Optimized cost and management efficiency for data-centric applications, combining substantial capacity with energy-aware operation and streamlined firmware updates to support predictable budgeting and maintenance in enterprise environments.

Technical Details of WD Ultrastar DC SN655

• Capacity: 3.84 TB
• Form Factor: U.3 Internal 15 mm
• Interface: PCI Express NVMe 4.0 (PCIe Gen4 x4)
• Drive Type: Read-Intensive Enterprise SSD

How to install WD Ultrastar DC SN655

Installing the WD Ultrastar DC SN655 is straightforward in compatible data-center servers, storage enclosures, or backplanes that support U.3 form factors and PCIe NVMe drives. Follow these general steps to ensure a smooth deployment:

• Power down the host system and disconnect from power. Ground yourself to prevent electrostatic discharge and handle the drive with care.
• Identify an appropriate U.3 backplane slot or NVMe-facing bay that accommodates a 15 mm internal drive and supports PCIe Gen4 NVMe connectivity.
• Install the SN655 into the designated drive bay or hot-swap tray, ensuring a secure fit and proper seating in the backplane or adapter connectors.
• Power on the system and enter the BIOS/UEFI or management console to verify that the drive is detected by the NVMe controller and recognized in the storage topology.
• In the operating system, initialize the drive as required by your storage strategy (RAID, storage pool, or direct NVMe provisioning) and apply any available firmware updates to maximize performance and reliability.
• Monitor drive temperatures and health metrics during initial operation, and configure appropriate cooling and airflow to maintain sustained read-intensive performance in the data-center environment.

Frequently asked questions

• Q: What workloads is the WD Ultrastar DC SN655 best suited for? A: It excels in read-intensive enterprise workloads such as database read caches, analytics accelerators, streaming and content delivery caches, and data warehouse read pathways within cloud and on-prem deployments.
• Q: What kind of endurance and reliability can I expect? A: The SN655 is built for enterprise reliability with endurance suitable for long-term, read-dominant workloads and consistent performance, backed by the Ultrastar engineering standards and vendor support.
• Q: Is this drive compatible with standard PCIe Gen4 servers and backplanes? A: Yes. The SN655 is designed for PCIe 4.0 NVMe infrastructure and U.3-compatible backplanes, making it suitable for a wide range of modern data-center environments.
• Q: Can it be used in NVMe over Fabrics configurations or mixed storage arrays? A: It is primarily intended for direct NVMe deployments in servers or storage backplanes. NVMe over Fabrics support depends on host, fabric adapters, and software stack used in the environment.
• Q: What cooling and environmental considerations are recommended? A: Follow the data-center’s standard enterprise cooling guidelines for NVMe drives; ensure adequate airflow, monitor drive temperatures under load, and adhere to vendor environmental specifications for sustained operation.