Meta open-sources MetaRoCE, a clean-sheet RDMA transport for AI-scale Ethernet

MetaRoCE：为 AI 规模以太网打造的全新 RDMA 传输协议

Meta released the MetaRoCE spec, a reference implementation, and a compliance test suite through OCP. It abandons the traditional RoCE assumption that switches must preserve order and losslessness—instead, the NIC handles out-of-order arrival, packet spraying, and congestion control natively. Every packet carries its own destination, so data lands directly in memory with no reorder buffer or head-of-line blocking. Meta has validated the design on clusters of hundreds of thousands of GPUs across regions; tail latency in all-reduce and response times for distributed inference both benefit. The post does not disclose specific performance benchmarks but states the protocol was built from scratch for million-GPU Ethernet.

Why it matters: Meta open-sourced a redesigned RDMA transport that handles out-of-order delivery on the NIC, validated on hundreds of thousands of GPUs. Directly useful for large-scale training infra teams, but it's an infrastructure-layer innovation somewhat removed from most AI practitioner...