Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE
Brand: Mellanox | Category: Transceivers & Cables
SKU: MEL-MCX4121A-ACAT | Part #: MCX4121A-ACAT | MPN: MCX4121A-ACAT
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About the Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE
The Mellanox MCX4121A-ACAT ConnectX-4 Lx EN adapter delivers dual-port 10/25GbE connectivity using SFP28 optics compatible with 10GBASE-SR and 25GBASE-SR transceivers, supporting multimode OM3/OM4 fibre up to 100 meters and single-mode OS2 fibre for extended reach. This low-profile, half-height PCIe 3.0 x8 network adapter is engineered for high-performance data centre environments where bandwidth efficiency and flexible speed scaling matter. Mellanox's ConnectX-4 Lx EN series combines advanced offload engines—including TCP/UDP/IP checksum, TSO, LRO, and tunnel offloads for VXLAN and NVGRE—with RoCE v1/v2 RDMA support and up to 128 virtual functions per port, enabling sophisticated workload acceleration and network virtualisation at the edge of modern compute clusters.
Network engineers and IT procurement teams select the MCX4121A-ACAT to bridge the gap between legacy 10GbE infrastructure and emerging 25GbE deployments without requiring wholesale platform redesign. Its support for Data Centre Bridging (DCB), Priority Flow Control (PFC), and Enhanced Transmission Selection (ETS) ensures lossless Ethernet for storage and AI workloads, while VMware ESXi, Linux, and Windows Server compatibility make it a versatile choice across heterogeneous environments. Power consumption of approximately 7.5W keeps thermal footprints minimal in dense server racks, and the dual-port design reduces slot count compared to single-port alternatives.
Omnixon Global stocks the Mellanox MCX4121A-ACAT as part of our comprehensive transceivers and cables portfolio, serving enterprise customers across the UAE and the broader Middle East region. Whether you are expanding a data centre fabric, upgrading cluster interconnects, or integrating high-speed storage networks, our technical team can validate compatibility with your infrastructure. Request a quotation through Omnixon Global to discuss volume pricing, lead times, and integration support for your next-generation network deployment.
Technical Specifications
| Brand | Mellanox |
| Category | Transceivers & Cables |
| SKU | MEL-MCX4121A-ACAT |
| Part Number | MCX4121A-ACAT |
| Condition | New |
| Capacity | 25Gb |
| Form Factor | HHHL |
| Interface | PCIe 3.0 x8 |
| Speed | 10/25GbE |
| Manufacturer Part Number | MCX4121A-ACAT |
| Product Series | ConnectX-4 Lx EN |
| Number of Ports | 2 |
| Port Interface | SFP28 |
| Supported Link Speeds | 10GbE, 25GbE |
| Host Interface | PCIe 3.0 x8 |
| Form Factor | Low-profile (half-height) |
| RDMA Support | RoCE v1 and v2 |
| SR-IOV Virtual Functions | Up to 128 VFs per port |
| Offload Engines | TCP/UDP/IP checksum, TSO, LRO, VXLAN, NVGRE tunnel offloads |
| Flow Control | Priority Flow Control (PFC), Enhanced Transmission Selection (ETS) |
| Data Center Bridging | DCB / IEEE 802.1Qbb / IEEE 802.1Qaz |
| Operating System Support | Linux, Windows Server, VMware ESXi |
| Management Interface | PCIe management, NC-SI |
| SFP28 Compatibility | 10GBASE-SR, 25GBASE-SR, Direct Attach Copper (DAC), Active Optical Cable (AOC) |
| Operating Temperature | 0°C to 55°C |
| Power Consumption (typical) | Approximately 7.5 W |
Frequently Asked Questions about Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE
What does the Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE do?
The Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE is enterprise IT hardware deployed in production data centers, server rooms, and edge sites across the GCC and EMEA region.
What are the headline specs of the Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE?
Key specifications for the Mellanox MCX4121A-ACAT ConnectX-4 Lx EN Adapter, 2x SFP28, 10/25GbE: capacity 25Gb; form factor HHHL; interface PCIe 3.0 x8; new condition; adapter family ConnectX-4 Lx EN Adapter; network ports 2x SFP28; supported speed 10/25GbE; host interface PCIe 3.0 x8; form factor HHHL; use case High-performance server networking, virtualization, storage, AI, and cloud. Manufacturer part number MCX4121A-ACAT. For the full datasheet with electrical, environmental, and compliance details, contact our pre-sales engineering team.