{
  "_NOTE": "ZeRO Stage 2 for full-parameter SFT on single H200 SXM. Stage 2 shards gradients (not params) and offloads optimizer states to CPU RAM. No optimizer block here — Adafactor is configured in the training script directly, because DeepSpeed's optimizer config conflicts with custom optimizers passed to the Trainer.",

  "bf16": {
    "enabled": true
  },

  "zero_optimization": {
    "stage": 2,

    "offload_optimizer": {
      "device": "cpu",
      "pin_memory": true
    },

    "offload_param": {
      "device": "none"
    },

    "overlap_comm": true,
    "contiguous_gradients": true,
    "reduce_scatter": true
  },

  "gradient_clipping": 1.0,
  "gradient_accumulation_steps": 8,
  "train_micro_batch_size_per_gpu": 1,
  "steps_per_print": 10
}