Identity & Definition
This enterprise Ethernet OCP network adapter, the NVIDIA Mellanox MCX4421A-ACQN, is a ConnectX-4 Lx EN dual-port 25GbE Ethernet adapter in OCP 2.0 Type 1 mezzanine form factor with two SFP28 connectors and host management support. This is an Ethernet-only adapter — it does not support InfiniBand. Condition: Refurbished — tested by T.E.S IT-SOLUTIONS.
Engineering Context
The ConnectX-4 Lx delivers 25GbE throughput on each of two SFP28 ports (50Gb/s aggregate) over a PCIe 3.0 x8 interface via the OCP 2.0 Type 1 mezzanine connector. The adapter supports RoCE v2 RDMA, VXLAN/NVGRE encapsulation, and SR-IOV. Each SFP28 port also supports backward-compatible 10GbE operation with SFP+ optics. Host management support enables out-of-band NIC management through the OCP mezzanine interface.
Deployment & Use Cases
Dual 25GbE server connectivity in OCP-compliant server platforms for redundancy or link aggregation. Cloud and hyperscale data centers where PCIe slots must be preserved for GPUs or storage accelerators. NVMe-oF and iSCSI storage connectivity at 25Gb/s with RoCE v2 RDMA. Virtualized VMware ESXi or KVM environments requiring SR-IOV with dual-port redundancy.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX4421A-ACQN
ASIC: ConnectX-4 Lx
Type: Ethernet Adapter (OCP 2.0 Type 1)
Speed: 25GbE per port (50Gb/s aggregate)
Ports: 2x SFP28
Host Interface: PCIe 3.0 x8 (via OCP 2.0 connector)
Host Management: Yes (OCP Type 1)
RDMA: RoCE v2
Condition: Refurbished
Compatibility & Hard Constraints
OCP 2.0 Type 1 Only: Requires OCP 2.0 Type 1 mezzanine slot. Does not fit standard PCIe slots or OCP 3.0. For standard PCIe dual 25GbE, use MCX4121A-ACAT. Ethernet Only: ConnectX-4 Lx does not support InfiniBand. SFP28 Ports: Accept SFP28 (25GbE) and SFP+ (10GbE) transceivers/cables. Do not accept QSFP modules. Dual Port: For single-port OCP 2.0 25GbE, use MCX4411A-ACQN. Predecessor: ConnectX-3 Pro OCP adapters. Successor: ConnectX-5/ConnectX-6 OCP 3.0 adapters.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS tests every refurbished OCP adapter for mezzanine connector integrity, dual-port connectivity, and firmware version before shipment. Technical consultation available for OCP server compatibility. Global shipping with tracking. 1–3 business day handling.