LLM Bottleneck Analysis

Why it matters

Bottleneck analysis directs spend. Optimizing the wrong resource wastes weeks.

The architecture

Check GPU util; check memory bw; check NVLink/InfiniBand; check CPU dispatch.

Classify with roofline.

How it works end to end

SM util high = compute-bound.

HBM util high = memory-bound.

NIC util high = comms-bound.