Autoresearch round 2: smear, backout, and hyperparameter tuning

New architectural features:
- Smear: mix previous token embedding into current position via learned
  gate, providing cheap bigram-like info (works in training + KV cache)
- Backout: subtract learned fraction of mid-layer residual before logit
  projection to remove low-level features

Hyperparameter tuning:
- Muon momentum warmdown 0.97→0.90 during LR warmdown phase
- Non-uniform per-layer init: resid_lambdas 1.15→1.05, x0_lambdas 0.20→0.05
- c_fc init scale 0.4x, QK norm scale 1.2, sliding window seq_len/4
- Speedrun data:params ratio reduced to 8

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
Andrej Karpathy
2026-03-14 17:03:06 +00:00
parent f068604948
commit a825e63f81
4 changed files with 73 additions and 18 deletions
+2 -2
View File
@@ -69,8 +69,8 @@ python -m scripts.tok_eval
echo "Waiting for dataset download to complete..."
wait $DATASET_DOWNLOAD_PID
# d24 model (slightly undertrained to beat GPT-2 => decrease data:params ratio from compute optimal 10.5 (default) to 9.5)
torchrun --standalone --nproc_per_node=8 -m scripts.base_train -- --depth=24 --target-param-data-ratio=9.5 --device-batch-size=16 --fp8 --run=$WANDB_RUN
# d24 model (slightly undertrained to beat GPT-2 => decrease data:params ratio from compute optimal 10.5 (default) to 8)
torchrun --standalone --nproc_per_node=8 -m scripts.base_train -- --depth=24 --target-param-data-ratio=8 --device-batch-size=16 --fp8 --run=$WANDB_RUN
# evaluate the model: CORE metric, BPB on train/val, and draw samples
torchrun --standalone --nproc_per_node=8 -m scripts.base_eval -- --device-batch-size=16