NVIDIA Mellanox MCX313A-BCCT ConnectX-3 Pro EN Adapter Card, Single-Port QSFP+, 40/56GbE: This is a single-port Ethernet network interface card based on the NVIDIA Mellanox ConnectX-3 Pro silicon. The card is Ethernet-only (the “EN” suffix) and runs at 40GbE or 56GbE on a single QSFP+ port. This is NOT a VPI card; it does NOT support InfiniBand mode — use the MCX353A-FCCT for VPI. The Pro silicon adds RoCE v2 and VXLAN/NVGRE overlay offloads beyond the base ConnectX-3 EN. This is a refurbished unit tested by T.E.S IT-SOLUTIONS.
Engineering Context
The card uses one ConnectX-3 Pro ASIC and exposes a single QSFP+ cage. Bandwidth is bounded by the PCIe 3.0 x8 host interface at 8GT/s per lane (effective ~63Gb/s aggregate), enough to saturate one 56GbE link. The Pro silicon adds NVGRE and VXLAN encapsulation/decapsulation offloads, plus RDMA over Converged Ethernet v2 (RoCE v2) routable over IP. Stateless TCP/IP offloads (TSO, LSO, GRO) are supported. SR-IOV with up to 127 virtual functions enables direct VM-to-NIC passthrough. The card uses a tall (full-height) PCIe bracket.
Deployment & Use Cases
40GbE/56GbE Ethernet uplinks for storage servers (Ceph, ZFS over iSER). Ethernet-only HPC clusters running RoCE v2 for RDMA workloads. Software-defined networking deployments using VXLAN or NVGRE overlays. Virtualized hosts using SR-IOV passthrough for line-rate VM networking. Migration from 10GbE bonded links to a single 40GbE port. Data center spine-leaf where the host needs only Ethernet.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number (MPN): MCX313A-BCCT
Product Line: ConnectX-3 Pro EN
Ports: Single-Port QSFP+
Ethernet Speed: 40GbE or 56GbE (also 10GbE)
Protocol Mode: Ethernet only (NOT VPI)
Host Interface: PCIe 3.0 x8 (8GT/s)
Form Factor: Tall (full-height) bracket
RDMA: RoCE v1 and RoCE v2
Overlay Offloads: VXLAN, NVGRE encap/decap
Virtualization: SR-IOV (up to 127 VFs)
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Requires a PCIe 3.0 x8 (or wider) slot. PCIe 2.0 slots will work but bandwidth is halved. Compatible with NVIDIA Mellanox SX1000 series and Spectrum SN2000 series Ethernet switches; 56GbE only operates against Mellanox switches that support proprietary 56GbE (it is not an IEEE standard). Driver support requires MLNX_OFED or upstream Linux mlx4 drivers; the ConnectX-3 generation is NOT supported by the newer mlx5 driver. Does NOT support InfiniBand — the port is hard-wired to Ethernet mode. The QSFP+ cage accepts QSFP/QSFP+ media; no native QSFP28 (100G) support.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS bench-tests every ConnectX-3 Pro EN card for Ethernet link training, RoCE loopback, and PCIe link width before shipment. Visit T.E.S IT-SOLUTIONS for warranty terms and global shipping. Standard handling time 1–3 business days.