NVIDIA Mellanox MCX4111A-ACAT ConnectX-4 Lx EN Adapter, 25GbE, Single-Port SFP28, PCIe 3.0 x8: This enterprise network interface card (NIC) is the NVIDIA Mellanox ConnectX-4 Lx, part number MCX4111A-ACAT. It is a single-port 25 Gigabit Ethernet adapter based on the ConnectX-4 Lx ASIC. The ACAT variant indicates Ethernet-only with crypto enabled and a tall bracket. This is a new unit.
Engineering Context
The ConnectX-4 Lx is the cost-optimized member of the ConnectX-4 family, delivering 25 Gb/s throughput through a single SFP28 port over a PCIe 3.0 x8 host interface (63 Gb/s bidirectional bandwidth). The Lx variant supports hardware offloads including RoCE v2, VXLAN/NVGRE encapsulation, and SR-IOV (up to 512 VFs). It is designed for environments where 25GbE provides the optimal cost-per-gigabit compared to 10GbE or 100GbE. The SFP28 port is backward-compatible with SFP+ at 10GbE, providing an upgrade path without cabling changes. Power consumption is typically under 12W.
Deployment & Use Cases
25GbE server connectivity for cloud and enterprise data centers migrating from 10GbE. NVMe-oF and iSCSI storage networking at 25 Gb/s. Virtualized environments on VMware ESXi, Hyper-V, or KVM with SR-IOV for VM-level network isolation. HPC cluster interconnect where 25GbE provides sufficient bandwidth per node. Backward-compatible 10GbE operation using SFP+ transceivers or DAC cables.
Technical Specifications
- OEM: NVIDIA Mellanox
- Part Number: MCX4111A-ACAT
- ASIC: ConnectX-4 Lx
- Type: Ethernet Network Adapter (NIC)
- Speed: 25GbE (also supports 10GbE with SFP+ cables/transceivers)
- Ports: 1x SFP28
- Host Interface: PCIe 3.0 x8
- Protocols: RoCE v2, VXLAN, NVGRE, SR-IOV
- SR-IOV VFs: Up to 512
- Power Consumption: ~12W typical
- Bracket: Tall (Full-Height)
- Condition: New
Compatibility & Hard Constraints
Ethernet Only: ConnectX-4 Lx does not support InfiniBand. For InfiniBand, use ConnectX-4 VPI variants (MCX455A or MCX456A series). SFP28 Port: Accepts SFP28 (25GbE) and SFP+ (10GbE) transceivers and cables. Does not accept QSFP modules. PCIe 3.0 x8: Requires a physical x8 or x16 slot. Will operate at reduced bandwidth in x4 slots. Single Port: One SFP28 port. For dual-port 25GbE, use MCX4121A-ACAT. Tall Bracket: Full-height bracket. Low-profile servers require a bracket swap. Predecessor: ConnectX-3 Pro EN (10GbE). Successor: ConnectX-5 EN (25/50GbE).
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS supplies new ConnectX-4 Lx adapters with expert consultation on NIC selection, firmware compatibility, and network architecture planning. Global shipping with 1–3 business day handling and full tracking.