Quick Comparison Table
| Feature | ConnectX-5 | ConnectX-6 |
|---|---|---|
| Max Speed | 100Gb/s | 200Gb/s (HDR) / 100GbE (HDR100) |
| PCIe Interface | PCIe 3.0/4.0 x16 | PCIe 4.0 x16 |
| GPUDirect | GPUDirect RDMA | GPUDirect RDMA + Storage |
When to Choose ConnectX-5
ConnectX-5 is the better value choice when your workload does not need 200GbE/HDR speeds. Used ConnectX-5 adapters cost 40-60% less than equivalent ConnectX-6 models.
When to Choose ConnectX-6
ConnectX-6 adds GPUDirect Storage and hardware-accelerated TLS/IPsec encryption. Required for HDR InfiniBand fabrics and AI/ML training clusters.
The Verdict
ConnectX-5 delivers approximately 95% of ConnectX-6 performance at 40-60% lower cost. Choose ConnectX-5 for budget deployments, ConnectX-6 for AI/ML and security.