Mellanox ConnectX-5 CX516A EN 2-Port QSFP28 50GbE Network Adapter
MCX516A-GCAT / CX516A
The Mellanox ConnectX-5 CX516A EN is a dual-port 50Gb Ethernet network interface card (NIC) designed for high-performance computing (HPC), cloud infrastructure, and data-intensive workloads. Built on the ConnectX-5 architecture, it delivers low latency, high throughput, and advanced hardware offloads to significantly reduce CPU overhead in modern data centers.
Part Number Identification
The following part numbers reference the same Mellanox ConnectX-5 CX516A EN adapter:
Device Type & Classification
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Device Type: Ethernet Network Interface Card (NIC)
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Series: Mellanox ConnectX-5
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Workload Focus: HPC, AI/ML, cloud, virtualization, and storage networking
Key Specifications
| Attribute |
Specification |
| Ethernet Data Rate |
50 Gb/s per port (dual-port) |
| Total Ports |
2 × QSFP28 |
| Host Interface |
PCI Express 3.0 x16 (backward compatible with PCIe 2.0 / 1.1) |
| Form Factor |
Low-profile plug-in card |
| Cabling Support |
QSFP28 copper or optical (transceivers sold separately) |
| Latency |
Sub-700 nanoseconds |
| Message Rate |
Very high message throughput (optimized for HPC) |
Note: Some configurations and firmware modes may support up to 100GbE aggregate bandwidth, depending on system and port configuration.
Offloads & Acceleration Features
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RDMA over Converged Ethernet (RoCE)
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NVMe over Fabrics (NVMf) target offloads
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Open vSwitch (OvS) hardware offloads
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Advanced packet processing and congestion control
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CPU offload acceleration for virtualized and containerized environments
Compatibility & Use Cases
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Compatible with standard PCIe x16 server slots
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Supported across Linux, Windows, VMware ESXi, and major cloud stacks
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Ideal for:
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High-performance computing (HPC)
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Data analytics & AI workloads
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Cloud and hyperscale infrastructure
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Software-defined storage and NVMe-oF
