Topology Study

Key Insight

Analyzing cluster network topology reveals the physical arrangement of GPU-GPU and node-to-node connections. By running tools like nvidia-smi (specifically nvidia-smi topo -m), developers can map the speed hierarchy of their hardware—identifying which paths utilize fast NVLink interconnects and which must route through slower PCIe buses or network switches. Understanding this routing allows for the optimization of collective communication patterns, ensuring that heavy data exchanges are mapped to high-bandwidth pathways.