pcie

Normalize link directions, count collective bytes, and see why a gradient reduction can outlast its real overlap window.

Compare host-staged and direct GPU-to-NIC transfers, count traffic at each boundary, and check transport selection before blaming a slow collective on missing GPUDirect.

Follow a host buffer across a NUMA boundary, calculate the cost with declared bandwidths, and align CPU workers and memory with the GPU that consumes the data.

Size adapter and full-parameter jobs before comparing RTX PRO 6000 and H100. Test memory headroom, MIG packing, software support and real communication costs.

Compare serialized and overlapped storage paths, then test whether direct GPU I/O improves the actual pipeline stage.

Handle an inaccessible GPU with bounded recovery and preserved evidence, without treating a reboot or repeat count as proof of root cause.