InfiniBand · IB
A low-latency lossless fabric with native RDMA, the historical default for non-blocking AI training back-ends.
Current numbers
2x400GbEConnectX-8: the single 800 Gb/s physical port runs Ethernet as 2×400GbE (single 800GbE link unsupported; XDR IB carries 800G on the same port) — the dual-plane substrate
~70%share of new AI infrastructure deployments choosing Ethernet/RoCEv2 over InfiniBand as parity closes
~1–2.5 usend-to-end RDMA fabric latency (NIC-to-NIC through one switch hop): InfiniBand ~1–2 µs, tuned RoCEv2 ~1.5–2.5 µs — microseconds, vs milliseconds for WAN