---
license: other
library_name: pytorch
tags:
- math
- code
- pretraining
- custom-architecture
- vathos
- pico
language:
- en
pipeline_tag: text-generation
---

# GUIDO-small 200M (bugfixed)

A 195M-parameter math/code-oriented language model, pretrained from scratch on a math-heavy corpus.
Custom architecture (Vathos PiCOFormer): gated attention, smear-gate, identity-at-init, UDLP MLP,
RoPE, tied embeddings, fp32-master weights with bf16 autocast.

> ⚠️ This is a **research checkpoint**. Architecture is custom (not HF-compatible) — requires the
> bundled `vathos/` package + `modeling_guido.py` to load.

## Eval

| | greedy | maj@16 (T=0.6, top_p=0.95, top_k=40) | pass@16 |
|---|---|---|---|
| **GSM8K** | 43.0% | **57.5%** | 77.5% |
| **MATH-500** | 21.0% | **30.0%** | 53.75% |

Numbers from `eval_distill.py` (greedy, N=200/100) and `eval_sc.py` (maj@16, N=80/80).

## Architecture

- **Shape**: 24 layers × 768 d_model × 12 heads × 64 head_dim × 3072 d_ff
- **Vocab**: 32,768 (Mathstral SPM tokenizer)
- **Position**: RoPE base 1e6, max_len 8192
- **Norm**: RMSNorm, qk-norm
- **Attention**: Multihead Gated (Modded-NanoGPT PR#117 style sparse output gate, gate_input_dim=12)
- **MLP**: VariableUDLP with LeakyReLU² activation, identity-at-init
- **Logit softcap**: 30.0
- **Tied embedding**: yes
- **Total params**: 195,092,992 (~195M)

## Training

- **Tokens seen**: 4.19B (16000 iter × 4 GPUs × 32 batch × 2048 seq)
- **Optimizer**: Muon (Newton-Schulz5) on 2D matrices (lr=0.01) + Adam on embedding (lr=0.005) + scalars (lr=0.04)
- **Schedule**: WSD (warmup 300 → plateau → linear warmdown last 60% to lr×1e-3)
- **Precision**: fp32 master weights + bf16 autocast (cce kernel gets bf16 cast at boundary)
- **Hardware**: 4× A100 64GB (Leonardo CINECA), ~3h wall

### Data mixture (corpus_v2)

| weight | shard | tokens (B) |
|---|---|---|
| 0.34 | OpenMathInstruct-2 (14M docs) | 6.79 |
| 0.14 | TinyGSM (full) | 2.70 |
| 0.10 | OpenMathReasoning subset | 1.50 |
| 0.07 | NuminaMath-1.5 | 0.41 |
| 0.05 | NuminaMath-CoT | 0.48 |
| 0.22 | FineWeb-Edu score≥3 (sample-10BT) | 3.00 |
| 0.08 | Cosmopedia subset | 1.19 |

Math 70% / NL 30%. Tokenizer: `mistralai/Mathstral-7B-v0.1`. Decontamination: canonical-hash vs MATH-500 and GSM8K test (note: not fuzzy-decon).

## How to load

### Quick start

```bash
pip install -r requirements.txt
```

```python
from huggingface_hub import snapshot_download
local_dir = snapshot_download(repo_id="Paerle/GUIDO_test_200M", token="<your_token>")

import sys, torch
sys.path.insert(0, local_dir + "/vathos")
sys.path.insert(0, local_dir)
import modeling_guido as m
from transformers import AutoTokenizer

# Inferenza arch dal ckpt (così non serve config)
state = torch.load(local_dir + "/pytorch_model.bin", map_location="cpu", weights_only=False)
sd = state["model"]
hp = m.HP()
hp.head_dim = 64
hp.d_model = sd["backbone.embedder.embedding.weight"].shape[1]
hp.n_heads = hp.d_model // hp.head_dim
hp.d_ff = sd["backbone.blocks.0.channel_mixer.expand.weight"].shape[0]
hp.n_layers = max(int(k.split("blocks.")[1].split(".")[0]) for k in sd if "blocks." in k) + 1
model = m.PiCOFormerLM(hp, vocab_size=sd["backbone.embedder.embedding.weight"].shape[0])
model.load_state_dict(sd, strict=False)
model = model.cuda().bfloat16().eval()
tok = AutoTokenizer.from_pretrained("mistralai/Mathstral-7B-v0.1")
```

See [`inference_example.py`](./inference_example.py) for a complete generation example
(temperature, top-p, top-k sampling).

## Files

| file | description |
|---|---|
| `pytorch_model.bin` | model weights (fp32 master, 745MB) |
| `config.json` | architecture + HP + eval results |
| `modeling_guido.py` | model definition (`PiCOFormerLM` + Muon optimizer + reader; only PiCOFormerLM/HP needed for inference) |
| `inference_example.py` | minimal load + generate example |
| `vathos/` | bundled Vathos package (custom backbone — see github.com/MarioPaerle/Aplos) |
| `requirements.txt` | deps (torch, transformers, cut-cross-entropy) |

## Known limitations

- **Decontamination**: canonical-hash only. ~7% of MATH-500 has near-duplicates in OpenMathInstruct-2
  augmentation (audited). Real MATH-500 capability is ~21% greedy, not inflated by overt memorization.
- **No instruction tuning**: this is a base pretrain. No SFT / RLHF.
- **Domain**: heavily math-skewed. NL is 30% (FineWeb-Edu + Cosmopedia) — basic fluency but not chat-style.
- **Tokenizer dependency**: requires `mistralai/Mathstral-7B-v0.1` tokenizer from HF.

## Hardware/precision notes

- Inference works fine in **bf16** (just call `.bfloat16()`). Weights are stored fp32 — 745MB on disk
  but ~390MB GPU memory after `.bfloat16()`.
- Custom CUDA kernels: uses `cut_cross_entropy` (Apple) for fused linear+CE in training.
  For inference you can replace with standard `F.linear + F.cross_entropy`.

## Architecture sketch

```
    input_ids
        │
   embedder (tied) ──────────────────────────┐
        │                                    │
   smear_gate (sparse on first 12 dims) ─────│ x0
        │                                    │
   [24× block]                                │
    ├── spatial: gated_attn + RoPE + qk-norm │
    ├── channel: VariableUDLP (LeakyReLU²)    │
    └── + x0_lambda × x0  ───────────────────┘
        │
   final_norm
        │
   tied unembed → cce / softcap 30 → logits
```

## License & citation

Vathos backbone (custom by Mario Paerle): https://github.com/MarioPaerle/Aplos
Model weights: research/private. Contact owner for usage terms.