NVIDIA Mellanox ConnectX-4 MCX415A-BCAT
Single-Port 40/56GbE QSFP28 Adapter, PCIe 3.0 x16
Host Interface
PCIe 3.0 x16
Port Count
1-port
Port Speed & Connector Type
40GbE/56GbE, QSFP28 (56GbE requires Mellanox switch)
RDMA / Network Protocol
RoCE v2 (RDMA over Converged Ethernet)
Controller / ASIC
MT27708A0-FDCF-CE (ConnectX-4 EN)
Product Description
The NVIDIA Mellanox ConnectX-4 EN MCX415A-BCAT is a single-port 40/56 Gigabit Ethernet adapter built on the ConnectX-4 EN controller (MT27708A0-FDCF-CE), using a PCIe 3.0 x16 host interface to provide maximum available bandwidth to a single QSFP28 port. The wider x16 interface removes host-side bandwidth constraints that can occur on x8 slots, making this card well suited to workloads that need to sustain near-line-rate 40/56GbE throughput, such as storage networking and HPC-adjacent applications. When connected to a Mellanox switch, the port can operate at 56GbE Ethernet speed for additional headroom. The card supports RDMA over Converged Ethernet (RoCE v2) to offload data transport from the host CPU, along with the broader hardware offload set of the ConnectX-4 EN generation. The MCX415A-BCAT is a common choice where server chassis provide PCIe x16 slots and administrators want to future-proof bandwidth headroom on a single-port design.