ETTR · Effective Training Time Ratio
The share of wall-clock time a training job spends making forward progress rather than restarting, checkpointing, or waiting on failures; the honest utilization metric for training clusters.
Current numbers
0.70 → 0.93Meta hypothetical dedicated 16,000-GPU RSC-1 case, assuming nonblocking checkpoint writes: modeled ETTR at 60-min versus 5-min intervals