- run 12: dim1664/22L true-GQA 1.05B base, seq1024, 6.765B FineWeb tokens,
81h on 8x5090. Fixed eval v1 @seq1024 = 2.7410 vs v11 2.7467 — a real but
marginal gain; v11->v12 is a capacity-only step on fixed data, so the ~0.2%
return confirms the 1B base is now data-limited.
- run 13: three SFT stages from the v12 base (synthetic / anchor /
real-mix-repair). The pipeline works and produces a chat-shaped model that
follows the format and stops, but none of the variants is a stable
high-quality chat model — bottleneck is SFT data quality + selection signal
(val loss decouples from generation quality), not infra.
- scripts/run_v12_phase.sh wrapper + chat_alpha_fixed_prompts.txt eval set.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
