Question 240
Following repair of this NVIDIA AI infrastructure defect: A 400G optical fabric link remains up but forward error correction counters increase rapidly during NCCL burn-in. Which verification is most decisive?
Explanation
Correct Answer
Check that A cable correction stabilizes pre-FEC and post-FEC indicators during the same sustained test. The result ties the observed fault to the targeted action: Inspect FEC and symbol counters, optical power and cable condition rather than using carrier state alone.
Incorrect Answers
The option would apply to “A high-speed NIC link shows error spikes only after adjacent power cables are rerouted tightly against the data assembly”. The decisive evidence is that The rerouted cable passes the sustained link-quality test with stable error counters. This question instead requires “A cable correction stabilizes pre-FEC and post-FEC indicators during the same sustained test”.
That observation does not establish operating effectiveness of Inspect FEC and symbol counters, optical power and cable condition rather than using carrier state alone. The needed evidence is that A cable correction stabilizes pre-FEC and post-FEC indicators during the same sustained test.
This is weaker evidence because Link-up status can hide marginal high-speed electrical or optical signal integrity. The independent test must show that A cable correction stabilizes pre-FEC and post-FEC indicators during the same sustained test.