Dante-2B

A 2.1B parameter bilingual Italian/English language model, trained entirely from scratch.

Dante-2B is a decoder-only transformer built by a single developer on 2× NVIDIA H200 NVL GPUs. Everything is native — the tokenizer, the architecture, the training pipeline — no fine-tune of an existing English model, no retrofitted multilingual vocabulary. Italian is a first-class citizen from byte zero.

Why Dante-2B?

Most "Italian" language models are English-first architectures with Italian bolted on during fine-tuning. Their tokenizers fragment Italian text into too many subwords, wasting context window and degrading fluency. Dante-2B takes a different path: the tokenizer was trained on a balanced Italian/English corpus from the start, so Italian apostrophe contractions (l', dell', un'), accented vowels, and common morphological patterns are single tokens — not sequences of three.

This is not a research lab effort with 512 GPUs. It's a from-scratch build on commodity hardware, with every engineering decision documented — including the failures.

Architecture

Dante-2B uses a pure Llama-style architecture optimized for training speed on limited hardware.

Tokenizer

A custom 64K BPE tokenizer trained on a character-balanced subset of the corpus (45% Italian, 45% English, 10% code).

Key properties:

• Italian accented vowels (à, è, é, ì, ò, ù) are always single tokens
• Italian apostrophe contractions (l'intelligenza, dell'algoritmo) are handled as single tokens
• Custom pre-tokenization regex preserves Italian morphology
• 36 special tokens including ChatML markers, thinking tokens, tool-use tokens, and expert routing tokens (future-proofing)

Fertility (tokens per word): ~1.35 Italian, ~1.20 English. For comparison, LLaMA's tokenizer scores ~1.85 on Italian.

Training

Phase 1 — Base Pretraining

90B tokens at sequence length 2,048 over ~57,200 steps.

• Optimizer: AdamW (β₁=0.9, β₂=0.95, weight decay 0.1)
• LR schedule: cosine, 3e-4 → 3e-5, 2,000-step warmup
• Batch size: micro_batch 24 × grad_accum 16 × 2 GPUs = 1,572,864 tokens/step
• Infrastructure: DeepSpeed ZeRO-2, FP8 (torchao), torch.compile (reduce-overhead), Flash Attention 2
• Throughput: ~88–89K tokens/sec, 28% MFU
• Final loss: ~1.85–1.93

Phase 2 — Continual Pretraining (Context Extension)

30B tokens at sequence length 4,096 over ~28,600 steps.

• LR schedule: cosine, 6e-5 → 6e-6, 500-step warmup
• Purpose: extend context window from 2,048 → 4,096 while consolidating learned representations
• Final loss: ~1.75–1.80 (expected plateau — gains manifest in downstream performance)
• Inference test: coherent Italian at 125.7 tok/s

Phase 3 — Supervised Fine-Tuning (SFT)

540K conversations (approximately 40% Italian), 1 epoch in ~3.5 hours.

• Micro_batch 12, grad_accum 10, ~89K tok/s, 33.4% MFU
• Eval loss: 1.23 (declining toward ~1.15)
• Strategy: single-epoch SFT to avoid overfitting
• Loss masking: only assistant turns contribute to loss; user turns and headers are masked with -100

SFT Datasets:

• HuggingFaceH4/no_robots
• OpenAssistant/oasst1 (via Guanaco)
• HuggingFaceH4/ultrachat_200k
• efederici/capybara-claude-15k-ita
• anakin87/fine-instructions-ita-70k
• Mattimax/Camoscio-ITA
• mchl-labs/stambecco_data_it
• teelinsan/camoscio
• DeepMount00/Sonnet-3.5-ITA-INSTRUCT
• DeepMount00/italian_conversations

Pretraining Data

The pretraining corpus is a bilingual mix (approximately 45% Italian, 45% English, 10% code by character count):

Italian: FineWeb-2 IT, FineWiki IT, Italian Public Domain (PleIAs), Gazzetta Ufficiale, EuroParl IT, FinePDFs IT, Clean mC4 IT

English: FineWeb-Edu (100B sample), FineWiki EN

Code: StarCoderData

Chat Format

Dante-2B uses a ChatML-style template:

<|begin_of_text|><|start_header|>user<|end_header|>
Come funziona la fotosintesi?<|eot|>
<|start_header|>assistant<|end_header|>
La fotosintesi è il processo attraverso cui le piante convertono...

Usage

import torch
from tokenizers import Tokenizer
from model_architecture import DanteConfig, DanteModel

# Load model
config = DanteConfig.load("config.json")
model = DanteModel(config)
model.load_state_dict(torch.load("model.pt", map_location="cpu"), strict=False)
model.eval().cuda()

# Load tokenizer
tokenizer = Tokenizer.from_file("tokenizer.json")

# Chat
prompt = "<|begin_of_text|><|start_header|>user<|end_header|>\nCiao, come stai?<|eot|>\n<|start_header|>assistant<|end_header|>\n"
input_ids = torch.tensor([tokenizer.encode(prompt).ids], device="cuda")

with torch.no_grad():
    # Use KV-cache for efficient generation
    kv_cache = None
    for _ in range(256):
        out = model(input_ids if kv_cache is None else input_ids[:, -1:],
                    kv_cache=kv_cache, use_cache=True)
        kv_cache = out["kv_cache"]
        next_id = out["logits"][:, -1].argmax(dim=-1, keepdim=True)
        input_ids = torch.cat([input_ids, next_id], dim=-1)
        token = tokenizer.decode([next_id.item()])
        if token in ["<|eot|>", "<|end_of_text|>"]:
            break
        print(token, end="", flush=True)

Tip: use repetition_penalty=1.15 for longer generations to avoid repetition loops.

Limitations

• Scale: At 2.1B parameters, Dante-2B is not competing with 7B+ models on complex reasoning. It is a capable small model for Italian-language tasks, on-device deployment, and research.
• Knowledge cutoff: The pretraining data has a knowledge cutoff determined by the source datasets (primarily 2023–2024 web crawls).
• Benchmarks: Formal evaluation on ITA-Bench and standard benchmarks is in progress and will be added here.
• Safety: This model has not undergone RLHF or safety-specific alignment. Use responsibly.

Training Stack

Repository Structure

├── model_architecture.py   # DanteConfig + DanteModel (full architecture)
├── config.json             # Model configuration
├── tokenizer.json          # 64K BPE tokenizer
├── model.pt                # Model weights
└── README.md               # This file

The full training codebase — from corpus download to SFT — is available on GitHub: [link to be added]

Citation

If you use Dante-2B in your research or applications, please cite:

@misc{angeletti2025dante2b,
  title={Dante-2B: A Bilingual Italian/English Language Model Trained from Scratch},
  author={Fabio Angeletti},
  year={2025},
  url={https://huggingface.co/leafsrls/dante-2b}
}

About

Dante-2B is built and maintained by Fabio Angeletti, PhD in Computer Engineering, Adjunct Professor at LUISS and LUISS Business School, and Founder & CEO of LEAF srls.

LEAF is a specialized AI company based in Italy, operating at the intersection of Artificial Intelligence, Machine Learning, IoT, and Cybersecurity. We deliver secure, efficient, and transformative digital strategies — from AI model development and system integration to low-power wireless monitoring and edge AI deployment. Our mission is to empower businesses to navigate and succeed in the digital economy through advanced technological innovation.

For collaborations, commercial licensing, or inquiries: info@leafsrls.com

License

This model is released under the Apache License 2.0. You are free to use, modify, and distribute it for any purpose, including commercial use.