NVIDIA Mellanox® MCX4341A-BCAA — ConnectX-4 Lx EN 40GbE Single-Port QSFP+ OCP 2.0 Mezzanine Adapter
Technical Identity
The NVIDIA Mellanox® MCX4341A-BCAA is a ConnectX-4 Lx EN single-port 40 Gigabit Ethernet network adapter built on the ConnectX-4 Lx ASIC. The card exposes one QSFP+ cage at 40GbE and ships in the OCP 2.0 Type 1 / WCS (Wiwynn Cloud Server) mezzanine form factor rather than a standard PCIe slot card. Host interface is PCI Express 3.0 x8. This is an Ethernet-only adapter (Lx ASIC) — it does not run InfiniBand and is not a VPI dual-protocol card. Condition: new, factory-sealed.
Specifications
Brand: NVIDIA Mellanox
Model / MPN: MCX4341A-BCAA
Product family: ConnectX-4 Lx EN Network Adapter
ASIC: ConnectX-4 Lx
Protocol: Ethernet only (Lx ASIC, no InfiniBand)
Port configuration: 1 × QSFP+ (single-port)
Line rate: 40GbE
Host interface: PCI Express 3.0 x8
Form factor: OCP 2.0 Type 1 mezzanine (WCS — Wiwynn Cloud Server)
RDMA: RoCE v1 / RoCE v2
Storage offload: NVMe-oF (over RoCE), T10-DIF data-integrity offload
Virtualization / SDN: SR-IOV, ASAP² (Accelerated Switching and Packet Processing) OVS offload
Tunnel offloads: VXLAN, NVGRE, Geneve, GTP encap / decap
Condition: New, factory-sealed
What This Is NOT
NOT an InfiniBand or VPI dual-protocol card. ConnectX-4 Lx is Ethernet only — no IB, no port-mode switching.
NOT a standard PCIe slot card. Form factor is OCP 2.0 Type 1 / WCS mezzanine — requires an OCP-compatible server chassis, not a generic ATX / EATX PCIe slot.
NOT a Multi-Host or socket-direct variant. Standard single-host adapter — one PCIe root complex, one MAC instance.
NOT a 25GbE / 50GbE / 100GbE card. Line rate is fixed at 40GbE on a single QSFP+ port.
NOT a different ConnectX generation. ASIC is ConnectX-4 Lx — firmware and driver must match this exact generation, not ConnectX-3, ConnectX-5 or ConnectX-6.
NOT bundled with cables, transceivers, breakout brackets, or OCP carrier — sold standalone.
Compatibility & Constraints
Compatible head-end switches: NVIDIA Spectrum / Spectrum-2 Ethernet switches at 40GbE, or legacy SwitchX-2 in Ethernet mode. Any standards-compliant 40GbE QSFP+ switch will interoperate.
Compatible cabling: 40GbE QSFP+ DAC (passive / active copper), 40GbE QSFP+ AOC, or 40GBASE-SR4 / LR4 QSFP+ optical transceivers with matching MMF / SMF fiber.
Drivers: NVIDIA MLNX_OFED (Linux), in-box mlx5_core (upstream Linux), WinOF-2 (Windows Server), nmlx5 (VMware ESXi).
Host platform: OCP 2.0 Type 1 mezzanine slot on a compatible chassis (e.g. Wiwynn / Open Compute servers). Not installable in a standard PCIe expansion slot without an OCP-to-PCIe carrier.
Firmware: ConnectX-4 Lx firmware branch only. Verify firmware version before deploying in production.
Frequently Asked Questions (FAQ)
Q. What is the NVIDIA Mellanox MCX4341A-BCAA?
The MCX4341A-BCAA is a ConnectX-4 Lx EN single-port 40GbE QSFP+ network adapter in the OCP 2.0 Type 1 / WCS mezzanine form factor, with a PCIe 3.0 x8 host interface. It is Ethernet only (Lx ASIC, no InfiniBand) and supports RoCE v1/v2, SR-IOV, ASAP² OVS offload, and NVMe-oF.
Q. Does this card support InfiniBand or VPI mode?
No. ConnectX-4 Lx is an Ethernet-only ASIC. There is no InfiniBand support and no VPI port-mode switching on Lx silicon. For VPI dual-protocol or native InfiniBand at this generation, use the full ConnectX-4 (non-Lx) MCX455 / MCX456 series instead.
Q. What switches and cables work with the MCX4341A-BCAA?
Any 40GbE QSFP+ Ethernet switch. NVIDIA Spectrum or Spectrum-2 Ethernet switches at 40GbE are the canonical pairing; SwitchX-2 in Ethernet mode and third-party 40GbE switches also interoperate. Cabling: 40GbE QSFP+ DAC, AOC, or 40GBASE-SR4 / LR4 optical transceivers.
Q. Will this card fit a standard PCIe slot?
No. The MCX4341A-BCAA is an OCP 2.0 Type 1 / WCS mezzanine card, not a standard PCIe expansion card. It installs into an OCP-compatible chassis mezzanine slot. Confirm your server chassis supports OCP 2.0 Type 1 before purchase.
Q. What workloads does the MCX4341A-BCAA accelerate?
Typical deployments: virtualized data-center hosts with SR-IOV, NVMe-oF storage initiators and targets over RoCE v2, software-defined networking (SDN / NFV) with ASAP² hardware Open vSwitch offload, and converged 40GbE Ethernet fabrics in OCP server racks. Not positioned for AI / ML training fabrics — at 40GbE single-port, this card targets enterprise virtualization and cloud server connectivity rather than GPU-cluster east-west traffic.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
New, factory-sealed in original NVIDIA Mellanox packaging where included. All units ship from EU stock with professional anti-static packaging and global B2B shipping. Technical consultation for OCP / data-center fabric design is included at no extra cost.
Why buy from T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS is a Europe-based NVIDIA Mellanox specialist serving HPC, AI, and enterprise data-center procurement teams since 2007. We focus on a single brand so every unit is identified by MPN, NVIDIA P/N, and ASIC generation before it ships, and every customer gets free pre-sale compatibility advice for switch, adapter, and cable pairing. Multi-currency B2B invoicing, EU stock with worldwide express options, and direct technical contact with our engineering team — not a call-center.