Enterprise SSD Interface Technology Innovations: PCIe, SAS, U.2, NVMe, NVMe‑oF, and ZNS

The content is based on the ODCC‑2022 Enterprise SSD Technology and Application Report and covers overall enterprise SSD storage status, innovative technologies, testing methods, and controller vendor analysis.

PCIe Interface : Uses differential transmission for high interference immunity, supports full‑duplex multi‑lane links (e.g., x1, x16 up to 6.4 GB/s), enabling high‑speed connections for networks, sound cards, and other devices.

SAS Interface : Provides a broad protocol suite for enterprise SSDs, featuring dual‑port and full‑duplex designs, mini‑SAS and mini‑SAS HD connectors, and support for up to four PHY interconnections, enhancing availability, scalability, and compatibility.

U.2 Interface : Offers compatibility with PCIe, SAS, and SATA, delivering high speed, low latency, and low power consumption; supports up to 32 Gbps (four times faster than SATA) and provides stronger thermal performance than M.2.

NVMe Protocol : Simplifies the storage stack, leverages PCIe lanes for low‑latency parallelism, supports up to 64 K I/O queues per device, reduces CPU overhead, and outperforms traditional SCSI‑based solutions.

NVMe‑oF (NVMe over Fabrics) : Extends NVMe across fabrics such as RDMA, RoCE, InfiniBand, and Fibre Channel, enabling remote, high‑concurrency access with microsecond‑level latency and supporting large‑scale data‑center deployments.

ZNS (Zoned Namespaces) : Divides the SSD namespace into zones, allowing sequential writes that lower write amplification (WAF close to 1), improve endurance, and free the full device capacity, benefiting big‑data and AI workloads.