Engineering at Meta

JUNE 12, 2024

Optimal connectivity between GPUs: Large-scale model training involves transferring vast amounts of data between GPUs in a synchronized fashion. There are two leading choices in the industry that fit these requirements: RoCE and InfiniBand fabrics. A slow data exchange between a subset of GPUs can compound and slow down the whole job.

Infiniband 141

Infiniband Data Centers Topology Network 141

Engineering at Meta

AUGUST 5, 2024

We ensure that there is enough ingress bandwidth on the rack switch to not hinder the training workload. The BE is a specialized fabric that connects all RDMA NICs in a non-blocking architecture, providing high bandwidth, low latency, and lossless transport between any two GPUs in the cluster, regardless of their physical location.

Network 132

Network Networking Topology Data Centers 132

Engineering at Meta

MARCH 12, 2024

The other cluster features an NVIDIA Quantum2 InfiniBand fabric. Through careful co-design of the network, software, and model architectures, we have successfully used both RoCE and InfiniBand clusters for large, GenAI workloads (including our ongoing training of Llama 3 on our RoCE cluster) without any network bottlenecks.

Infiniband 145

Infiniband Data Centers Server Network 145