NVIDIA Mellanox MCX516A-CDAT ConnectX-5 Ex EN 100GbE Dual-Port QSFP28 PCIe Gen4 x16 Network Adapter: This is a dual-port 100Gb/s Ethernet network interface card based on the ConnectX-5 Ex ASIC, with a PCIe Gen 4.0 x16 host interface and a tall bracket. This is a network adapter card, not a switch, transceiver, or breakout cable. This is a refurbished unit, tested by T.E.S IT-SOLUTIONS.
Engineering Context
The MCX516A-CDAT delivers up to 200 Gb/s of aggregate Ethernet throughput across two QSFP28 ports. PCIe Gen 4.0 x16 provides ~256 Gb/s of host bandwidth, ensuring both ports can run at full 100GbE simultaneously without host-side bottlenecks. The ConnectX-5 Ex ASIC includes hardware offloads for RoCE v2, Open vSwitch, NVMe-oF, GPUDirect RDMA, and overlay tunnels (VXLAN, Geneve, NVGRE). End-to-end latency is measured in single-digit microseconds for RoCE traffic.
Deployment & Use Cases
Hyperscale and enterprise data center compute nodes requiring dual 100GbE uplinks. AI/ML training clusters using RoCE v2 for GPU-to-GPU communication. NVMe-over-Fabrics storage targets and initiators. Software-defined networking with hardware-accelerated VXLAN/Geneve. Virtualization hosts running SR-IOV with up to 1K virtual functions per port.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX516A-CDAT
Product Family: ConnectX-5 Ex EN
Ports: 2 × QSFP28
Max Data Rate: 100GbE per port (200 Gb/s aggregate)
Host Interface: PCIe Gen 4.0 x16 (backward compatible with Gen 3.0)
Protocol: Ethernet (10/25/40/50/100GbE)
Form Factor: Standard PCIe HHHL with tall bracket
Offloads: RoCE v2, Overlay (VXLAN/Geneve/NVGRE), TCP/UDP/IP stateless, T10-DIF, NVMe-oF
Virtualization: SR-IOV, VirtIO acceleration
Management: NC-SI
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with x86 servers providing PCIe Gen 4.0 x16 (or Gen 3.0 x16 at reduced bandwidth) and Linux/Windows drivers from NVIDIA. Pairs with NVIDIA Spectrum SN2000/SN3000/SN4000 switches and 100GbE-capable QSFP28 transceivers, AOCs, and DACs. This is an Ethernet-only (EN) adapter; it does not run InfiniBand. Not compatible with OCP 3.0 chassis (this is a standard PCIe HHHL card). Tall bracket is installed; low-profile bracket is not included.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS bench-tests every refurbished ConnectX adapter for link, PCIe negotiation, and offload functionality before shipment. We provide expert consultation on 100GbE fabric design, global shipping, and a typical handling time of 1–3 business days.