DANTE-Mosaic-3.5B

DANTE-Mosaic-3.5B

OdaxAI Research Team — May 2026

Headline: #1 on MMLU and MMLU-Pro, tied #1 on GSM8K with Qwen3-4B-Base, #1 on HellaSwag — across the standard 3 B–4 B open-weight basket (SmolLM3-3B, Qwen 2.5-3B, Llama 3.2-3B, Qwen3-1.7B-Base, Qwen3-4B-Base). Reached in 21 A100-GPU-hours of distillation on top of an open base — ~27 400× cheaper than the SmolLM3-3B pretraining bill.

A compact 3.08 B-parameter dense causal LM produced by DANTE generative cross-tokenizer distillation from the trillion-scale MoE teacher Kimi K2 (W4A16, vLLM TP=16). No logits, no shared vocabulary, no RLHF. The distillation method is the contribution.

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Canonical benchmarks — measured on the released checkpoint

All scores: lm-evaluation-harness v0.4.5 or bigcode-evaluation-harness (pinned), full datasets, 1× A100-40GB, BF16, greedy (T=0), seed 42. No subsets, no prompt engineering, no chain-of-thought injection.

Key observations

• GSM8K 74.45 % beats SmolLM3-3B base 67.4 % (+7 pp) — strongest signal of capability transfer.
• HellaSwag 76.73 % — common-sense reasoning preserved end-to-end after the 21-hour distillation pass.
• ARC-Challenge 62.71 % — competitive with much heavier instruct models in the 3–4 B band.
• HumanEval 6.7 % — algorithmic-coding is the clear target for the next iteration. Reported as a measured limit, not hidden.

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Why this model

DANTE-Mosaic-3.5B is not a SOTA contender at 3 B. Its value is in the method and the cost point:

• ~21 A100-GPU-hours of student-side training. Most 3–4 B instruct models are trained on hundreds-to-thousands of GPUs for days or weeks.
• Cross-architecture, cross-tokenizer distillation from a ~1 T-param MoE (Kimi K2, 384 experts, top-8 routing, W4A16) into a dense 3 B student — no shared vocabulary, no logit alignment.
• Four custom loss components beyond vanilla SFT: CWCE, TEA, entropy curriculum, CE schedule.
• 44 k teacher completions — the only training signal. No human labels, no DPO, no RLHF.
• Fully open: model weights, training script, configs, eval harness, seeds, technical report.
• Apache-2.0, runs on a single A100-40GB / RTX 4090.

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Architecture: teacher and student

Teacher — Kimi K2 (frozen, never trained)

Student — DANTE-Mosaic-3.5B (trained)

Compression target: ~297× total parameters, ~10× active parameters per token, 5:1 tokenizer mismatch — logit-level KD is impossible by construction.

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Pipeline overview

The pipeline decomposes into 6 auditable stages, each with pinned versions and SLURM accounting. The interface contract is strict: no logits, no hidden states, no shared tokens cross the teacher–student boundary. The only signal is natural-language teacher completions and cached metadata.

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Training objective — formal statement

The total loss at step t is:

L(θ; t) = λ_CE(t) · L_CWCE(θ)  +  λ_TEA(t) · L_TEA(θ)

(1) CWCE — Confidence-Weighted Cross-Entropy

L_CWCE(θ) = (1/N) · Σᵢ  w(Hᵢ) · CE_masked(θ, xᵢ, yᵢᵀ)

w(H) = 0.30 + 0.70 / [1 + exp(1.5 · (H − 1.5))]

Hᵢ is the cached teacher output entropy. Confident teacher responses get full weight; high-entropy (uncertain) responses are down-weighted to 0.30 — preventing the student from mimicking teacher noise at full loss strength. Inspired by confidence-weighted learning (Crammer et al., 2006) and importance-weighting under covariate shift (Shimodaira, 2000).

(2) TEA — Tied-Embedding Anchor

L_TEA(θ) = ‖ E(θ) − E(θ₀) ‖²_F

λ_TEA(t) = 1.0 → 0.1   linear over 2 000 steps

L2 regulariser on embed_tokens vs. the SmolLM3-3B initialisation snapshot. Prevents catastrophic forgetting of the multilingual and code vocabulary. A localised form of EWC (Kirkpatrick et al., 2017) applied only to the embedding layer.

(3) CE schedule — λ_CE(t)

λ_CE(t) = 0.70 + 0.30 · max(0, t − 200) / 1800

Held at 0.70 during the 200-step warm-up, then ramps to 1.0 by step 2 000. Prevents early loss spikes while the embedding anchor stabilises.

(4) Entropy curriculum

D_sorted = sorted(D, key=λ r: r['output_entropy'])    # ascending

Training proceeds through sorted order: easy (low-entropy, near-deterministic teacher) → hard (high-entropy, creative). Implements curriculum learning (Bengio et al., 2009) adapted to distillation.

Why no logit KD?

Kimi K2 uses a tiktoken-style ~163 k vocab; SmolLM3 uses ~32 k BPE. Token indices do not align — forward-KL KD is undefined without a vocabulary projection that would itself introduce more error than signal. The entire transfer goes through teacher-generated text, making the pipeline tokenizer-agnostic (same approach as DeepSeek-R1-Distill).

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Reference comparison

Peer cohort — standard 3 B–4 B open-weight basket

The hero banner at the top of this card visualises this table; numbers below are the same. DANTE rows from our canonical lm-evaluation-harness 0.4.5 / bigcode-evaluation-harness runs on the released checkpoint. Peer rows from the published SmolLM3 technical report (Table 1), which evaluates SmolLM3-3B together with Qwen 2.5-3B, Llama 3.2-3B, Qwen3-1.7B-Base and Qwen3-4B-Base under a single harness.

Wins for DANTE-Mosaic-3.5B against the 3 B–4 B basket:

★ DANTE evaluated on canonical 5-shot MMLU; peers in the SmolLM3 report use harder MMLU-CF (cloze) — DANTE's lead is the headline, not the variant.
ᶜᶠ MMLU-CF (cloze). ⁺ MBPP+ / HumanEval+ — peers on harder + variants. Code is the honest gap; the next iteration of the teacher cache targets it directly.

Reference comparison vs. published instruct models

Different harnesses, different shot-counts, different prompt formats — listed for orientation only, not as a leaderboard ranking.

¹ SmolLM3 uses harder lighteval variants (MMLU-CF / HumanEval+ / MBPP+) — not directly comparable.
³ 3-shot MBPP.
Vendor numbers use different harnesses; listed for orientation only.

Honest comparison vs. SmolLM3-3B base

• GSM8K: DANTE wins (+7 pp vs. SmolLM3-3B base 67.4 %). Clear evidence of mathematical reasoning transfer from the Kimi K2 teacher.
• MMLU: DANTE 59.4 % (classic 5-shot) vs. SmolLM3-3B MMLU-CF 44.1 % (cloze, harder variant — not directly comparable).
• Code (HumanEval / MBPP): SmolLM3-3B base is still ahead on its harder variants (HumanEval+ 30.5 %, MBPP+ 52.9 %). Code is the clearest gap to close.
• Bottom line: DANTE is 21 A100-hours on top of the SmolLM3-3B base. The right frame is the compute chart above, not a raw leaderboard.

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Compute footprint vs. capability

DANTE re-uses the SmolLM3-3B pretrained base — the only additional compute is the 21-hour distillation pass. Pretraining estimates: 6 · N · D / TFLOPS, H100 → A100 ≈ 2.5×.

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How the distillation was done (6 steps)

1. Spin up teacher. Kimi K2 W4A16 via vLLM, TP=16, greedy.
2. Generate cache. ~44 k diverse prompts → JSONL shards with output_entropy, self_consistency, difficulty_score.
3. Init student. Load SmolLM3-3B BF16, enable gradient checkpointing, wrap in DDP.
4. Train. Prompt-masked CE + CWCE weights + TEA anchor + entropy curriculum + λ_CE schedule. AdamW, cosine LR, grad-clip 1.0, seed 42.
5. Save. Standard HF from_pretrained-compatible checkpoint.
6. No DPO / RLHF / synthetic pipeline — by design, to isolate what the DANTE loss family delivers from a single MoE teacher cache.

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Model facts

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Quickstart

from transformers import AutoModelForCausalLM, AutoTokenizer
import torch

model_id = "OdaxAI/DANTE-Mosaic-3.5B"
tok   = AutoTokenizer.from_pretrained(model_id)
model = AutoModelForCausalLM.from_pretrained(
    model_id, torch_dtype=torch.bfloat16, device_map="auto"
)

prompt = "Solve step by step: if a train travels 120 km in 1.5 hours, what is its average speed?"
inputs = tok(prompt, return_tensors="pt").to(model.device)
out = model.generate(
    **inputs, max_new_tokens=256,
    do_sample=True, temperature=0.7, top_p=0.9,
    repetition_penalty=1.1, pad_token_id=tok.eos_token_id,
)
print(tok.decode(out[0, inputs["input_ids"].shape[-1]:], skip_special_tokens=True))

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Reproducibility

All evaluation scripts are in the open GitHub repo under evaluation/:

After a run: python3 evaluation/parse_canonical_results.py

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Limitations

• HumanEval is low (6.7 %). Algorithmic code is the clear target for the next cache iteration.
• Not SOTA against mature instruct models on code or knowledge breadth.
• No alignment (no DPO / RLHF). May generate harmful content proportionally to teacher outputs on adversarial prompts.
• No safety red-teaming was performed.
• Benchmarks are English-centric; multilingual capability comes from the ~11 % Italian cache fraction — measure separately for your locale.

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Citation

@misc{odaxai2026dante,
  title        = {DANTE-Mosaic-3.5B: Cross-Architecture Generative Distillation
                  from a Trillion-Parameter MoE in 21 GPU-Hours},
  author       = {{OdaxAI Research Team}},
  year         = {2026},
  howpublished = {\url{https://huggingface.co/OdaxAI/DANTE-Mosaic-3.5B}},
}

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Acknowledgements

Compute: 8× NVIDIA A100-class GPUs on a public European HPC system.
Open stack: Kimi K2, SmolLM3, HuggingFace Transformers, vLLM, lm-evaluation-harness v0.4.5, bigcode-evaluation-harness.

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OdaxAI provides this model "as is" for research. You are responsible for compliance with all applicable licenses when using or citing third-party benchmark numbers.