NVIDIA Mellanox MCX4421A-ACAN ConnectX-4 Lx EN 25GbE Dual-Port SFP28 NIC: This is a dual-port 25 Gigabit Ethernet Network Interface Card (NIC) built on the Mellanox ConnectX-4 Lx ASIC, with SFP28 cage connectors and a PCIe 3.0 x8 host interface. The MCX4421A prefix denotes the OCP-style mezzanine form factor — the unit ships without a standard PCI bracket. This is an Ethernet-only adapter (Lx EN) and does NOT support InfiniBand. This is a brand-new, factory-sealed unit.
Engineering Context
The ConnectX-4 Lx ASIC delivers 25GbE per port using SerDes signaling at 25.78125 Gb/s with native RS-FEC support. SFP28 ports auto-negotiate down to 10GbE for backward compatibility with existing infrastructure. The adapter supports RDMA over Converged Ethernet (RoCE v1 and v2), SR-IOV with up to 127 virtual functions per port, hardware offloads for VXLAN, NVGRE, and GENEVE overlay encapsulation, and erasure coding offload for storage workloads. PCIe 3.0 x8 provides up to 64 Gb/s — sufficient for full-duplex dual-port 25GbE.
Deployment & Use Cases
Hyperscale and cloud server NIC for OCP-compatible chassis; 25GbE top-of-rack uplinks; NVMe-oF over RoCE storage initiators and targets; virtualization hosts with SR-IOV passthrough; container networking with hardware-accelerated overlays; and AI training data plane connectivity for cost-sensitive nodes that do not require ConnectX-6 or higher class adapters.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number (MPN): MCX4421A-ACAN
ASIC: ConnectX-4 Lx
Adapter Family: ConnectX-4 Lx EN (Ethernet only)
Ports: 2 × SFP28
Data Rate: 25GbE per port (auto-negotiates to 10GbE)
Host Interface: PCIe 3.0 x8
Form Factor: OCP-style mezzanine (bracket-less)
Offloads: RoCE v1/v2, SR-IOV (up to 127 VFs/port), VXLAN, NVGRE, GENEVE, erasure coding
FEC: RS-FEC for 25GbE
RoHS: R6 compliant
Condition: Brand New — Factory Sealed
Compatibility & Constraints
Requires an OCP-compatible host chassis or appropriate OCP-to-PCIe carrier — does NOT fit a standard PCIe slot directly without an adapter. SFP28 ports accept 25GBASE-SR, 25GBASE-LR transceivers, and 25G SFP28 DAC/AOC cables; ports also accept SFP+ 10GbE optics and DAC cables at the lower rate. Compatible with Mellanox Spectrum (SN2000-series) and any IEEE 25GbE switch from Cisco, Arista, Juniper, or HPE. NOT an InfiniBand adapter. Linux (MLNX_OFED or inbox), Windows Server, VMware ESXi, and FreeBSD all supported.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS supplies NEW, factory-sealed Mellanox networking hardware with verified part-number authenticity. Visit tes-itsolutions.com for our full ConnectX-4 Lx catalog, expert pre-sales fabric consultation, global shipping with 1–3 business day handling, and warranty support.