NVIDIA ConnectX Network Adapters: Core of Data Center Connectivity
ConnectX adapters provide RDMA, RoCE, and InfiniBand capabilities for AI training clusters, distributed storage, and HPC. This guide compares ConnectX-5, ConnectX-6, and ConnectX-7.
Specifications Comparison
| Specification | ConnectX-5 Ex | ConnectX-6 Lx | ConnectX-6 HX | ConnectX-7 |
|---|---|---|---|---|
| Max Port Speed | 100Gb/s | 25/50/100GbE | HDR 200Gb/s | NDR 400Gb/s |
| Ports | 2 | 2 | 2 | 2 |
| PCIe | Gen3 x16 | Gen4 x8 | Gen4 x16 | Gen5 x16 |
| RDMA | IB+RoCEv2 | RoCEv2 | IB+RoCEv2 | IB+RoCEv2 |
| RDMA Latency | ~0.8 us | ~1.0 us | ~0.6 us | ~0.5 us |
| Cache | 4 MB | 8 MB | 16 MB | 32 MB |
| SecureBoot | No | No | Yes | Yes |
| Power | ~25W | ~15W | ~40W | ~60W |
ConnectX-5 Ex: The Proven 100Gb/s Platform
Widely deployed in DGX A100 clusters (4 per DGX), 100GbE storage networks, and HPC EDR fabrics. Best for: Existing 100Gb/s deployments needing cost-effective replacement.
ConnectX-6 Lx: The Cost-Effective Ethernet Accelerator
25/50/100GbE with RoCEv2, 15W TDP. Best for: 25-100GbE Ethernet deployments needing RDMA without InfiniBand.
ConnectX-6 HX: The Dual-Mode HDR 200Gb/s Accelerator
200Gb/s InfiniBand or Ethernet, dual-port dual-mode (IB+Eth simultaneously). Best for: AI training clusters and 200Gb/s storage fabrics.
ConnectX-7: The NDR 400Gb/s Next-Gen Adapter
400Gb/s for H100/H200, PCIe Gen5, OCP 3.0 form factor. Best for: H100/H200 GPU deployments and 400Gb/s infrastructure.
Frequently Asked Questions
Can ConnectX-6 HX run IB on one port and Ethernet on the other?
Yes. Port 1 InfiniBand HDR, port 2 Ethernet 100GbE simultaneously. Common in DGX servers.
Which PCIe generation is needed?
ConnectX-5: Gen3 x16. ConnectX-6: Gen4 x8/x16. ConnectX-7: Gen5 x16. Adapters are backward-compatible at reduced bandwidth.
Browse our network adapters collection for availability.