NVIDIA Mellanox MCX415A-BCAT ConnectX-4 EN Network Interface Card, Single-Port QSFP28, up to 40/56 GbE, PCIe 3.0 x16: This is a server-class single-port Ethernet network adapter based on the ConnectX-4 EN ASIC. The QSFP28 cage supports 1/10/25/40 GbE and 56GbE FDR-Ethernet, and the host interface is a sixteen-lane PCIe 3.0 link. This is an Ethernet-only adapter (not VPI/InfiniBand), and it is not a switch or DPU. This is a refurbished unit.
Engineering Context
56GbE on this part refers to FDR-Ethernet, a Mellanox-specific extension that uses the InfiniBand FDR signaling rate over Ethernet framing for back-to-back Mellanox links. It is not part of the IEEE 802.3 standard and only interoperates with other NVIDIA/Mellanox endpoints. The card supports RDMA over Converged Ethernet (RoCE) v1/v2, hardware stateless TCP/UDP offloads, VXLAN/NVGRE encapsulation, and SR-IOV. PCIe 3.0 x16 provides ~126 Gb/s of usable host bandwidth — far in excess of a single 56GbE port's needs — leaving headroom for full-rate operation regardless of host CPU contention. End-to-end latency is sub-microsecond for RDMA verbs.
Deployment & Use Cases
Single-port 40GbE or 56GbE FDR-Ethernet host connectivity for compute or storage servers. Storage gateway servers between Mellanox 56GbE FDR-Ethernet fabrics and slower upstream networks. RoCEv2-based NVMe-over-Fabrics initiators where a single high-bandwidth port suffices. Lab and validation environments standardizing on a Mellanox-only 56GbE FDR-Ethernet topology. Compute nodes that need a wide PCIe 3.0 x16 lane width for full headroom under sustained load.
Technical Specifications
- OEM: NVIDIA Mellanox
- Part Number: MCX415A-BCAT
- Family / ASIC: ConnectX-4 EN
- Ports: 1 × QSFP28
- Max Data Rate: 56GbE FDR-Ethernet (also 40 / 25 / 10 / 1 GbE)
- Host Interface: PCIe 3.0 x16
- Form Factor: PCIe HHHL with tall bracket
- Stateless Offloads: TCP/UDP/IP checksum, TSO/LSO, RSS
- RDMA: RoCE v1, RoCE v2
- Virtualization: SR-IOV
- Tunnel Offloads: VXLAN, NVGRE, GENEVE
- Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Drivers in NVIDIA MLNX_EN / OFED for Linux, in-box on VMware ESXi, and in-box on Windows Server. 56GbE FDR-Ethernet is Mellanox-proprietary — interop at 56GbE requires another Mellanox endpoint; standards-compliant 50GbE or 40GbE is the correct choice for multi-vendor topologies. This card is Ethernet-only — it does NOT switch firmware to InfiniBand mode (not VPI). The QSFP28 cage accepts QSFP28 transceivers and DACs/AOCs; SFP28 cages require a QSA28 adapter. PCIe 3.0 x16 is a hard ceiling: a PCIe 3.0 x8 slot will physically fit but cap aggregate bandwidth.
Why Choose T.E.S IT-SOLUTIONS
Every ConnectX-4 EN adapter is bench-tested for link training, transceiver detection, RoCE functionality, and PCIe link width before shipment. T.E.S IT-SOLUTIONS provides expert consultation on Ethernet fabric design, global shipping, and 1–3 day order handling.