Identity & Definition
This 40GbE Ethernet network interface card is the NVIDIA Mellanox ConnectX-4 Lx EN 40GbE Single-Port NIC (MCX4341A-BCAA), a new PCIe adapter card sold by T.E.S IT-SOLUTIONS. The ConnectX-4 Lx is the cost-optimized, Ethernet-only variant of the ConnectX-4 family with a single QSFP28 port on a PCIe 3.0 x8 interface. This is a discrete adapter card, NOT a transceiver. The "Lx" designation means Ethernet-only — it does NOT support native InfiniBand. Condition: New.
Engineering Context
The ConnectX-4 Lx MCX4341A-BCAA provides Ethernet-only functionality with a subset of the full ConnectX-4 feature set. Despite being the Lx variant, it supports hardware-offloaded RoCE v2, SR-IOV (up to 256 VFs), VXLAN/NVGRE overlay offload, and stateless offloads. The single QSFP28 port operates at 40GbE maximum (also supports 10GbE and 25GbE). While the QSFP28 connector physically accepts 100G optics, the Lx silicon limits the port to 40Gb/s. The PCIe 3.0 x8 host interface provides 32 GT/s of host bandwidth. The ConnectX-4 Lx has been succeeded by ConnectX-5, ConnectX-6, and ConnectX-7 but remains widely deployed in 25/40GbE environments.
Deployment & Use Cases
The ConnectX-4 Lx MCX4341A-BCAA is deployed in virtualized server environments requiring 40GbE with SR-IOV and RoCE v2, cloud computing infrastructure with VXLAN/NVGRE overlay offload, NFS-over-RDMA storage networks using RoCE v2, and budget-conscious 40GbE deployments in Dell PowerEdge, HP ProLiant, and Lenovo ThinkSystem servers where InfiniBand is not required.
Technical Specifications
OEM: NVIDIA Mellanox
Product Line: ConnectX-4 Lx
Part Number (MPN): MCX4341A-BCAA
Port Speed: 40GbE (also 10GbE, 25GbE)
Ports: 1x QSFP28
Host Interface: PCIe 3.0 x8
Protocol: Ethernet only (no InfiniBand)
RDMA: RoCE v2
Offloads: SR-IOV (up to 256 VFs), VXLAN/NVGRE
Form Factor: Half-Height, Half-Length (HHHL)
Condition: New
Compatibility & Hard Constraints
The ConnectX-4 Lx MCX4341A-BCAA is Ethernet only — it does NOT support native InfiniBand fabrics despite sharing the QSFP28 physical interface. For InfiniBand or VPI capability, use ConnectX-4 (non-Lx) or ConnectX-5/6 VPI models. The QSFP28 port accepts QSFP+ (40G) DACs, AOCs, and transceivers but does NOT support 100GbE speeds — the Lx silicon limits to 40Gb/s. PCIe 3.0 x8 will function in x16 slots at x8 speed. Successors include ConnectX-5, ConnectX-6, and ConnectX-7 with higher speeds and expanded features.
Why Choose T.E.S IT-SOLUTIONS
Every NVIDIA Mellanox ConnectX NIC sold by T.E.S IT-SOLUTIONS is verified for correct firmware and functionality. T.E.S IT-SOLUTIONS provides technical consultation for NIC selection, RDMA deployment planning, and server compatibility verification. Orders ship within 1–3 business days with global delivery via DHL, FedEx, and UPS.