NVIDIA Mellanox MCX443M-BCBN ConnectX-4 EN, 40GbE Single-Port Multi-Host OCP Mezzanine Adapter: This is an OCP mezzanine network interface card based on the ConnectX-4 EN Ethernet controller, providing a single-port 40GbE QSFP28 connection with Multi-Host technology. Multi-Host enables a single physical port to be partitioned and shared across up to four independent host CPUs over PCIe. This is an OCP mezzanine form factor — it is NOT a standard PCIe slot card and does NOT include a PCIe bracket. This is a refurbished unit, tested by T.E.S IT-SOLUTIONS.
Engineering Context
NVIDIA Multi-Host technology allows the MCX443M-BCBN to act as a shared NIC for multiple compute nodes in a single chassis, reducing port count and cable cost in dense multi-node servers. The ConnectX-4 EN controller supports RoCE v1/v2, VXLAN/NVGRE tunneling offload, SR-IOV (up to 128 VFs), and stateless TCP/UDP/IP offloads. PCIe Gen3 x8 provides full line-rate bandwidth for 40GbE. The card uses a QSFP28 cage and is backward-compatible with QSFP+ optical and copper modules at 40GbE speed.
Deployment & Use Cases
Multi-node OCP server platforms (e.g., 4-node 2U chassis) where a single NIC is shared across compute sleds. Hyperscale storage targets that consolidate uplinks. Hyper-converged infrastructure where multi-host reduces TOR switch port consumption. 40GbE leaf-spine fabrics in private cloud and HPC clusters.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX443M-BCBN
Controller: ConnectX-4 EN
Form Factor: OCP Mezzanine
Ports: Single-Port (1x QSFP28)
Data Rate: 40GbE
Host Interface: PCIe Gen3 x8 (8 GT/s)
Multi-Host: Yes — supports up to 4 independent hosts
Bracket: None (OCP mezzanine)
Offloads: RoCE v1/v2, SR-IOV, VXLAN, NVGRE
Compliance: RoHS R6
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Requires an OCP-compliant motherboard with the matching mezzanine connector and Multi-Host signaling support. Will NOT fit standard PCIe slots. To use Multi-Host, the chassis must wire each PCIe x2 lane group to a separate host CPU. Compatible with Mellanox-certified 40G QSFP+ DACs, AOCs, and SR4/LR4 transceivers. Supports Ethernet only (not InfiniBand). Drivers: NVIDIA MLNX_OFED, MLNX_EN, or in-box Linux/Windows.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS tests every refurbished ConnectX-4 mezzanine card for link-up, port LED, and Multi-Host enumeration before shipment. Orders ship within 1–3 business days with global delivery and warranty coverage.