NVIDIA Mellanox MCX4111A-ACAT ConnectX-4 Lx EN 25GbE Single-Port SFP28 NIC, P/N 900-9X4B0-0013-0Q0: This is a single-port 25 Gigabit Ethernet network adapter based on the NVIDIA ConnectX-4 Lx EN ASIC, with a PCI Express Gen 3.0 x8 host interface and an SFP28 cage for the network port. This is an Ethernet-only Lx variant — it is not the VPI ConnectX-4 (MCX4xxxA-xCAT) and does not support InfiniBand. This unit is professionally refurbished and tested by T.E.S IT-SOLUTIONS.
Engineering Context
The MCX4111A-ACAT delivers 25Gb/s line rate on a single SFP28 port and provides hardware offloads designed for virtualized and cloud workloads. The ConnectX-4 Lx ASIC supports RDMA over Converged Ethernet (RoCE v1/v2), SR-IOV with multiple virtual functions, and stateless TCP/UDP offloads (checksum, TSO, LRO). PCI Express Gen 3.0 x8 provides up to 64 Gb/s of host bandwidth, eliminating PCIe bottlenecks at 25GbE line rate. The card ships with a tall (full-height) bracket installed.
Deployment & Use Cases
Server-side 25GbE uplink to top-of-rack Spectrum or Cumulus switches. Hyperconverged infrastructure nodes running VMware vSAN, Microsoft Storage Spaces Direct, or Nutanix AHV. KVM/OpenStack hosts using SR-IOV to give VMs near-native NIC performance. NVMe over Fabrics (NVMe-oF) initiator and target nodes using RoCE for low-latency block storage. Container/Kubernetes worker nodes needing high east-west bandwidth.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number (MPN): MCX4111A-ACAT
NVIDIA P/N: 900-9X4B0-0013-0Q0
ASIC: ConnectX-4 Lx EN
Data Rate: 25GbE (also supports 10GbE / 1GbE on the SFP28 cage)
Port Configuration: Single-Port SFP28
Host Interface: PCI Express Gen 3.0 x8
Bracket: Tall (Full Height)
Protocol Support: Ethernet only (no InfiniBand)
Offloads: RoCE v1/v2, SR-IOV, TCP/UDP/IP checksum, TSO, LRO
Manufacturer: NVIDIA Mellanox Technologies
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Requires a server with an available PCIe Gen3 x8 slot (or wider). Compatible with mainstream Linux distributions (RHEL, Ubuntu, SUSE) and VMware ESXi via NVIDIA/Mellanox in-box and OFED drivers. The SFP28 cage accepts NVIDIA-branded 25GbE/10GbE SFP28/SFP+ DACs, AOCs, and optical transceivers; third-party transceivers may require firmware coding allowance. This is the Lx Ethernet-only variant — it does not support InfiniBand SDR/QDR/FDR/EDR; for VPI dual-protocol use the ConnectX-4 (non-Lx) MCX455A/MCX456A series. Tall bracket installed; a low-profile bracket is not included.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS power-cycles, link-trains at 25GbE, and validates RoCE/SR-IOV functionality on every refurbished MCX4111A-ACAT before shipment. We provide compatibility verification, global delivery, and 1-3 day order handling. Visit https://www.tes-itsolutions.com for the full Mellanox NIC catalogue.