Within the node (gpu to gpu), it is infinity fabric. Externally, it is 8x400G NICs, which is the limitation of PCIeV5 anyway. We had a guy training SOTA model

Within the node (gpu to gpu), it is infinity fabric. Externally, it is 8x400G NICs, which is the limitation of PCIeV5 anyway. We had a guy training SOTA models on 9 of our MI300x boxes just fine. Networking wasn't the slow bit.