NVIDIA Mellanox MCX4131A-GCAT ConnectX-4 Lx EN 50GbE Single-Port QSFP28 Adapter: This is a single-port 50GbE Ethernet network interface card built on the NVIDIA ConnectX-4 Lx EN ASIC. The MCX4131A-GCAT is a PCIe Gen3 x8 adapter shipped with a tall bracket installed. This is an Ethernet-only adapter (not VPI), so it does NOT operate as InfiniBand. This is a new unit.
Engineering Context
The ConnectX-4 Lx EN family runs 25Gb/s NRZ SerDes; the GCAT variant aggregates two 25Gb/s lanes over a QSFP28 cage to deliver 50GbE on a single physical port. The card supports RDMA over Converged Ethernet (RoCE v1 and v2) for low-latency storage and HPC traffic. Hardware offloads cover TCP/UDP/IP checksum, large send offload (LSO), receive side scaling (RSS), and overlay encapsulation offload for VXLAN, NVGRE, and GENEVE. SR-IOV is supported with up to 256 virtual functions per port for VM acceleration.
Deployment & Use Cases
VMware ESXi with NSX-T overlay networking and VXLAN offload. Hyperconverged infrastructure (HCI) clusters running vSAN, Storage Spaces Direct, or Ceph. KVM/OpenStack tenant networks with SR-IOV passthrough. iSCSI, NFS, and NVMe-over-Fabrics (NVMe-oF) storage front-ends at 50GbE. NFV data plane processing with DPDK and OvS hardware offload.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX4131A-GCAT
Controller: ConnectX-4 Lx EN
Ports: 1x QSFP28
Data Rate: 50GbE (2x 25Gb/s NRZ)
Host Interface: PCIe 3.0 x8
Bracket: Tall bracket installed
RDMA: RoCE v1 / v2
Virtualization: SR-IOV (up to 256 VFs)
Overlay Offload: VXLAN, NVGRE, GENEVE
Protocol: Ethernet only (not VPI/InfiniBand)
Condition: New — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with 50GbE direct-attach copper (DAC) and active optical cables (AOC) in QSFP28 form factor, and with 50GbE-capable switches such as the NVIDIA Spectrum SN2000 series. Drivers are available for Linux (MLNX_OFED / inbox), Windows Server, VMware ESXi, and FreeBSD. Single-port card; does not support 4x25G breakout. Does NOT operate as InfiniBand — for VPI use the MCX455A or MCX456A series. Auto-negotiation to 40GbE depends on link partner capabilities and may require a compatible 40GbE QSFP+ optic on the far end.
Why Choose T.E.S IT-SOLUTIONS
Visit T.E.S IT-SOLUTIONS for tested NVIDIA Mellanox networking. Each adapter is bench-checked, firmware-noted, and packaged for safe transit. Order handling time is 1–3 business days with global shipping options.