NVIDIA Mellanox ConnectX-5 EN 25GbE Dual-Port SFP28 Ethernet Adapter - MCX512A-ACAT
This Ethernet network interface card (NIC) is the NVIDIA Mellanox MCX512A-ACAT, a ConnectX-5 EN dual-port 25GbE adapter with SFP28 connectors and PCIe 3.0 x8 interface. This is a new, factory-sealed unit from T.E.S IT-SOLUTIONS. It is NOT a ConnectX-6 or ConnectX-6 Dx adapter. It does NOT support InfiniBand protocols (Ethernet only).
Engineering Context
The MCX512A-ACAT is built on the ConnectX-5 ASIC and connects via PCIe Gen 3.0 x8 (SERDES at 8.0 GT/s), delivering up to 50 Gb/s aggregate bandwidth across both SFP28 ports. Each port operates at up to 25 Gb/s using NRZ signaling, with backward compatibility to 10 Gb/s and 1 Gb/s speeds. The adapter supports hardware offloads including RoCE v2, RDMA, SR-IOV (up to 1024 VFs), NVMe over Fabrics (NVMe-oF), VXLAN/GRE tunnel offload, and stateless TCP/UDP/IP checksum and segmentation offloads. It ships with a tall (full-height) bracket.
Deployment and Use Cases
The MCX512A-ACAT is deployed in virtualized cloud environments running VMware ESXi, KVM, or Hyper-V with SR-IOV passthrough for high-density VM networking at 25GbE. It serves NVMe-oF storage fabrics connecting initiators to NVMe targets over 25GbE RDMA. In web-scale data centers, dual-port 25GbE provides cost-effective per-server bandwidth for microservices, container orchestration (Kubernetes), and east-west traffic in spine-leaf architectures on Dell PowerEdge, HPE ProLiant, Lenovo ThinkSystem, and Supermicro servers.
Technical Specifications
Model: MCX512A-ACAT
Product Type: ConnectX-5 EN Ethernet Adapter Card (NIC)
Ports: 2x SFP28
Speed per Port: Up to 25 Gb/s (NRZ); also supports 10/1 GbE
Aggregate Bandwidth: 50 Gb/s
PCIe Interface: Gen 3.0 x8
Form Factor: PCIe HHHL (Half-Height, Half-Length)
Bracket: Tall (Full-Height)
Offloads: RoCE v2, RDMA, SR-IOV (1024 VFs), NVMe-oF, VXLAN/GRE
Condition: New (factory-sealed)
Compatibility and Hard Constraints
The MCX512A-ACAT uses SFP28 connectors and requires SFP28 DAC cables, SFP28 AOC cables, or SFP28 transceivers. It is NOT compatible with QSFP28 or QSFP56 cabling (different connector form factor). It fits standard PCIe x8 or x16 slots in rack-mount and tower servers. The tall bracket ships installed; a low-profile bracket may need to be sourced separately for half-height chassis. This is an Ethernet-only adapter and does NOT support InfiniBand protocols. The MCX516A-CCAT is the ConnectX-5 EN dual-port 100GbE QSFP28 variant. This adapter is compatible with VMware ESXi, RHEL, Ubuntu, Windows Server, Proxmox, and FreeBSD. Driver support via NVIDIA MLNX_OFED or inbox drivers.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS provides this MCX512A-ACAT as a new, factory-sealed unit. Technical consultation is available to verify compatibility with your specific server platform and cabling infrastructure. Global shipping is available with 1-3 business day handling time.