How do people measure power usage of GPUs at large (32x) self-hosted setups or small multi-rack setups? I've seen some PDUs which collect and transmit data, but I'm unsure of the processes and if/how people do this on small builds.

Currently, I collect NVML nvmlDeviceGetPowerUsage, polled at 100ms during inference, peak and mean per request, and get this type of data:

model mean-power range (W) spread stdev qwen3-8b 114.3-121.9 7.6W 1.17 llama-3.1-8b-instruct 104.7-122.1 17.4W 4.29 qwen2.5-1.5b-instruct 53.7-73.0 19.3W 5.23 mistral-7b-instruct-v0.3 96.2-120.0 23.8W 6.01 qwen2.5-7b-instruct 88.7-124.5 35.8W 7.73 gemma-3-1b-it 49.4-56.7 7.3W 2.13

this is per-GPU, single-card data - I don't know whether anything like per-request attribution survives at rack scale, or whether monitoring there happens entirely at the PDU/BMC level instead.