Record: dTTT + BigramHash 3072×112 — val_bpb 1.0800 (3-seed mean)

[aamodbhatt]

Record Summary

Final submitted score: val_bpb 1.0800 (std 0.0002)
Reference neural roundtrip: 1.09935 (std 0.00007)

Hardware: 8×H100 SXM | Artifact: ≤15.9 MB | Training: ≤600s

What changed

• BigramHash 3072×112 (up from 2048×128 in PR Record: Discriminative TTT — val_bpb 1.0807 (3-seed mean) #1351): more expressive n-gram features following PR Record: AR Self-Gen GPTQ + XSA-all + BigramHash 3072×112 — val_bpb 1.11473 (3-seed mean) #1019/1405 config
• All other hyperparameters identical to PR Record: Discriminative TTT — val_bpb 1.0807 (3-seed mean) #1351 (dTTT 10ep, AdamW LR=0.0005, freeze=0, per-block LR 0.3×–1.0×, GPTQ damp=0.005, QK_GAIN=5.0, WARMDOWN=4000, XSA all-layers)

3-Seed Results

Seed	final val_bpb	roundtrip val_bpb	train_s	eval_s	bytes_total
1337	1.08017	1.09941	600	102	15,873,363
42	1.07980	1.09926	600	102	15,895,227
2025	1.08018	1.09938	600	78	15,865,471
Mean	1.0800	1.09935	-	-	-
Std	0.0002	0.00007	-	-	-

Submission Checklist

• One folder added: records/track_10min_16mb/2026-04-06_dTTT_BH3072_11L_8xH100/
• README.md, submission.json, train_gpt.py, 3 seed logs present
• Training ≤ 600s (all seeds stopped at wallclock cap)
• All artifacts ≤ 16,000,000 bytes
• No tokenizer or dataset edits
• Track A — no eval-time adaptation: standard autoregressive sliding-window eval only

Metric Verification

• Score from final_int6_sliding_window_exact in each seed log
• Roundtrip from final_int6_roundtrip_exact in each seed log
• Artifact size from Total submission size int6+lzma in each seed log

Credits

• Discriminative TTT (per-block adaptive LR): PR Record: Discriminative TTT — val_bpb 1.0807 (3-seed mean) #1351
• Full Hessian GPTQ + XSA-all: PR Record: AR Self-Gen GPTQ + XSA-all + BigramHash 3072×112 — val_bpb 1.11473 (3-seed mean) #1019
• BigramHash 3072×112 config: PR Record: Scylla + GPTQ + BH3072 — val_bpb 1.0856 (3-seed mean) #1405