NVIDIA Mellanox MCX346A-BCQN ConnectX-3 Pro EN Dual-Port 40GbE QSFP+ OCP Mezzanine Card: This is a dual-port 40 Gigabit Ethernet network adapter built in the Open Compute Project (OCP) Mezzanine 2.0 form factor with NC-SI and IPMI sideband management. It uses the ConnectX-3 Pro EN controller and supports RoCE for hardware-accelerated RDMA over Ethernet. This is an Ethernet-only EN variant — it is NOT a VPI card and does NOT operate in InfiniBand mode. This is a refurbished unit.
Engineering Context
The MCX346A-BCQN is built on the Mellanox ConnectX-3 Pro EN ASIC and uses a PCIe 3.0 x8 host interface. It implements RoCE v1 and v2 for kernel-bypass RDMA over standard Ethernet fabrics, plus stateless TCP/UDP/IP offload and overlay network offloads (VXLAN, NVGRE) for virtualized data centers. SR-IOV exposes virtual functions to guest operating systems with hardware-enforced isolation. NC-SI and IPMI sideband channels let the BMC manage the adapter independently of the host OS state.
Deployment & Use Cases
OCP-compliant cloud server fleets requiring dual 40GbE uplinks. Hyperconverged infrastructure (vSAN, Storage Spaces Direct) using RoCE for east-west storage traffic. NVMe-oF over RoCE storage back-ends. Hadoop and Spark clusters where 40GbE removes the network bottleneck for shuffle-heavy workloads. NFV and telco edge nodes that need OCP form-factor adapters with sideband management.
Technical Specifications
- OEM: NVIDIA Mellanox
- Part Number: MCX346A-BCQN
- Controller: ConnectX-3 Pro EN
- Form Factor: OCP Mezzanine 2.0
- Ports: 2 × QSFP+
- Data Rate: 40GbE per port
- Host Interface: PCIe 3.0 x8
- Protocol Mode: Ethernet only (EN variant)
- RDMA: RoCE v1, RoCE v2
- Sideband Management: NC-SI, IPMI
- Overlay Offloads: VXLAN, NVGRE, GENEVE
- Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with OCP Mezzanine 2.0 slots in OCP-compliant servers (Wiwynn, Quanta QCT, Inspur, ZT Systems, and similar). Not compatible with standard PCIe expansion slots — the OCP form factor uses a different connector and mounting. Not compatible with InfiniBand fabrics; this EN-only model cannot be re-flashed to VPI mode. Requires QSFP+ DAC, AOC, or 40GBASE-SR4/LR4 transceivers for link operation. Older OCP Mezzanine 1.0 slots are not pin-compatible.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS link-tests both ports at 40GbE, verifies firmware revision, and inspects the OCP connector before shipment. We provide global shipping, pre-sale consultation on OCP server compatibility, and 1–3 business day handling. See tes-itsolutions.com for related ConnectX-3 Pro adapters.