Files
esh-pfi-infrastructure/docs/runbooks
vh b538fde6f0 caps: fv-ml1 250W / ana-ml3 200W — and nvidia-smi -pl caps BOARD power, not wall power
Operator set fv-ml1 at 250 W per card (83% of TGP, ~5% throughput) and ana-ml3 at 200 W
(67%, ~10-15%). Records the term that decides whether 250 W actually clears a 15 A feed,
because it is easy to drop: a power limit bounds BOARD power, and the wall sees that
divided by PSU efficiency.

Four cards at 250 W is 1000 W of board; add 180-300 W of host components and divide by
~0.90 and the plug sees ~1310-1445 W, against a 15 A circuit's 1440 W NEC continuous
derating -- an inference box serving all day being a continuous load. So 250 W lands ON
the limit rather than under it, where 200 W would give ~1090-1220 W with real margin.
The deciding term is the host draw, which is still an estimate, so the procedure is: set
250 W, verify at the plug under four-card load, fall back to 200 W if it reads near
1440 W. A cap is a claim; the ammeter is the verification.

Two consequences recorded alongside. Caps bound sustained draw and not transients -- the
enforcement window is short but not instantaneous -- and while a breaker's
thermal-magnetic curve forgives brief overload, a UPS's overload protection does not. So
250 W implicitly commits the fv-ml1 chassis to the PDU rather than behind the 1500 VA
unit, which it exceeds even capped. And ana-ml3's 200 W across only two cards is
deliberately conservative at 400 W total, relaxable if Anaheim's measured headroom beats
its trip history.
2026-09-13 00:28:49 -07:00
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