Optimize for sustained goodput, not peak FLOPS: at 100,000+ accelerator scale, a single component failure synchronously halts the entire training job, so the real throughput ceiling is set by failure detection, checkpointing, and restore speed rather than raw compute.
It relocates the dominant cost of large-scale compute from arithmetic to fault handling, meaning reliability engineering and checkpoint/restore mechanics — not more chips — determine effective training speed, and the same logic applies to any system where many workers must synchronize on a barrier.
In any tightly-synchronized fan-out system, goodput degrades with failure rate times worker count; resilience machinery (fast detection, cheap restart, frequent checkpointing) becomes a first-class performance feature rather than an operational afterthought.
FLOPS is a vanity metric; goodput and workload performance are what actually matter.
A single chip failure in a synchronous training job can bring the entire 100,000-chip computation to a halt.
Detecting, recovering from, and checkpointing failures continuously is like finding a needle in a haystack over hours, days, or weeks.