# S2 — Gradient flow check (constant tau=2, ~50M tokens) # Purpose: Lower tau gives sharper gates. Does predictor learn useful topology? # Any NLL drop below baseline (2.4569) = gradient flows correctly. # Run: python scripts/train.py --config configs/s2_gradient_flow.yaml # Model olmo_model_id: "allenai/OLMo-2-0425-1B" qwen_model_id: "Qwen/Qwen3-Embedding-0.6B" # Predictor predictor_hidden_dim: 1024 predictor_rank: 32 cascading_gate_k: 5.0 input_norm: "none" # Data dataset: "allenai/dolma" dataset_name: "v1_7" seq_len: 1024 batch_size: 4 micro_batch_size: 2 qwen_input_prefix: "" # Eval eval_skip: 10000 eval_size: 50 # Training — ~50M tokens = 12500 steps @ batch=4, seq=1024 total_steps: 12500 lr: 3e-4 weight_decay: 0.01 optimizer: "adamw" # Schedules — constant tau=2 (sharper gates than S1), no sparsity tau_init: 2.0 tau_final: 2.0 tau_schedule: "cosine" lambda_max: 0.0 lambda_warmup_frac: 0.2 # Logging wandb_project: "dagformer" wandb_run_name: "s2-gradient-flow" log_every: 10 eval_every: 500 # Checkpointing save_every: 2500 save_dir: "checkpoints/s2/" # Hardware num_gpus: 1