checkpoint_dir/train_results.json

{
    "epoch": 1.0,
    "total_flos": 3210595501381632.0,
    "train_loss": 1.177695571192053,
    "train_runtime": 189.533,
    "train_samples_per_second": 12.742,
    "train_steps_per_second": 3.187
}