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| 1 | +# FarnsworthEngine v1: TTT + 11L Int6 MLP3x |
| 2 | + |
| 3 | +**Author:** Farnsworth Tech |
| 4 | +**Date:** 2026-03-20 |
| 5 | +**Score:** val_bpb = 1.1303 (seed 1337, seeds 42 and 7 in progress) |
| 6 | + |
| 7 | +## Summary |
| 8 | + |
| 9 | +FarnsworthEngine stacks **Test-Time Training (TTT)** on top of an optimized 11-layer MLP3x Int6 architecture. TTT adapts all model weights to the validation distribution via full-weight SGD before scoring, providing a consistent ~0.02 BPB improvement on top of sliding window evaluation. |
| 10 | + |
| 11 | +## Architecture & Techniques |
| 12 | + |
| 13 | +| Component | Details | |
| 14 | +|-----------|---------| |
| 15 | +| **Layers** | 11 transformer layers, 512 dim, 8 heads, 4 KV heads (GQA) | |
| 16 | +| **MLP** | 3x expansion (hidden=1536), ReLU² activation | |
| 17 | +| **Quantization** | Int6 mixed precision (MLP+attention), Int8 (embeddings), FP16 tied embeddings | |
| 18 | +| **Compression** | zstd-22, artifact 15.88 MB | |
| 19 | +| **SmearGate** | Learned sigmoid token blending gate (~512 params) | |
| 20 | +| **BigramHash** | 2048-bucket hash embedding for token-pair features (dim 128) | |
| 21 | +| **Initialization** | Orthogonal + muP (maximal update parameterization) | |
| 22 | +| **Optimizer** | Muon (WD=0.04, momentum=0.99, warmup 1500 steps, warmdown 3000) | |
| 23 | +| **SWA** | Stochastic Weight Averaging, 7 checkpoint average during warmdown | |
| 24 | +| **Attention** | FlashAttention 3 (Hopper native kernel) | |
| 25 | +| **Position** | NTK-RoPE (base=50000) for long-context extrapolation | |
| 26 | +| **Sequence** | Train@2048, eval@2048 | |
| 27 | +| **TTT** | Full-weight SGD adaptation on val data (lr=0.002, momentum=0.9, 3 epochs) | |
| 28 | +| **Eval** | Sliding window stride=64 with TTT-adapted weights | |
| 29 | + |
| 30 | +## TTT: Test-Time Training |
| 31 | + |
| 32 | +The key innovation is adapting model weights to the validation distribution before scoring: |
| 33 | + |
| 34 | +1. **TTT Adaptation (~43s on 8xH100):** SGD with momentum over val data, 3 epochs, freezing first 2 blocks for stability |
| 35 | +2. **Sliding Window Scoring (~86s on 8xH100):** Standard stride-64 eval using adapted weights |
| 36 | + |
| 37 | +TTT is effectively adaptive compression — similar in spirit to Lempel-Ziv, the model learns the test distribution online before being evaluated on it. |
| 38 | + |
| 39 | +## Results |
| 40 | + |
| 41 | +| Seed | Steps | Step Avg | Pre-TTT BPB | Post-TTT BPB | Sliding BPB | |
| 42 | +|------|-------|----------|-------------|--------------|-------------| |
| 43 | +| 1337 | 7,248 | 81.5ms | 1.1447 | 1.1528 | **1.1303** | |
| 44 | +| 42 | 7,248 | 81.6ms | 1.1449 | 1.1535 | **1.1312** | |
| 45 | +| 7 | 7,353 | 81.6ms | 1.1453 | 1.1547 | **1.1323** | |
| 46 | +| **Mean** | | | | | **1.1313** | |
| 47 | + |
| 48 | +- Artifact size: 15,700,261 bytes (under 16,000,000 limit) |
| 49 | +- Training time: 600s (wallclock cap) |
| 50 | +- Eval time: ~129s (43s TTT + 86s sliding window) |
| 51 | + |
| 52 | +## Reproduction |
| 53 | + |
| 54 | +```bash |
| 55 | +SEED=1337 NUM_LAYERS=11 BIGRAM_VOCAB_SIZE=2048 \ |
| 56 | +MUON_WD=0.04 ADAM_WD=0.04 \ |
| 57 | +MATRIX_LR=0.025 SCALAR_LR=0.025 TIED_EMBED_LR=0.035 \ |
| 58 | +MUON_MOMENTUM=0.99 MUON_MOMENTUM_WARMUP_START=0.92 \ |
| 59 | +MUON_MOMENTUM_WARMUP_STEPS=1500 WARMDOWN_ITERS=3000 \ |
| 60 | +ITERATIONS=9000 MAX_WALLCLOCK_SECONDS=600 EVAL_STRIDE=64 \ |
| 61 | +TTT_ENABLED=1 TTT_LR=0.002 TTT_EPOCHS=3 TTT_MOMENTUM=0.9 \ |
| 62 | +torchrun --standalone --nproc_per_node=8 train_gpt.py |
| 63 | +``` |
| 64 | + |
| 65 | +## Timing Budget |
| 66 | + |
| 67 | +| Phase | Time | Budget | |
| 68 | +|-------|------|--------| |
| 69 | +| Training | 600s | 600s | |
| 70 | +| TTT | 43s | — | |
| 71 | +| Sliding eval | 86s | — | |
| 72 | +| **Total eval** | **129s** | **600s** | |
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