---
license: mit
language:
- en
tags:
- llama
- text-generation
- micro
- nano
- small
- base-model
- banana-mind
pipeline_tag: text-generation
library_name: transformers
datasets:
- HuggingFaceFW/fineweb-edu
---

# Vantora Micro

A **9,800-parameter** pure Llama-style causal language model, trained on a
100M-token slice of FineWeb-Edu. This is the "pure transformer" baseline in a
head-to-head comparison against a hybrid Mamba-2 + attention model of the same
size.

## Model Details

| Property | Value |
|---|---|
| Architecture | LlamaForCausalLM (pure transformer) |
| Parameters | 9,800 |
| Vocab size | 1024 (ByteLevel BPE) |
| Hidden size (d_model) | 8 |
| Intermediate size | 22 (MLP ratio 2.77) |
| Hidden layers | 2 |
| Attention heads | 1 |
| Head dim | 8 |
| Context length | 512 |
| RoPE theta | 10000.0 |
| RMSNorm eps | 1e-6 |
| Tied embeddings | Yes |
| Dtype | float32 |

## Training

- **Data:** first 100M tokens of `HuggingFaceFW/fineweb-edu` `sample-10BT`
- **Epochs:** 1 (100M total tokens seen)
- **Batch:** 128 × seq 256 (3,051 steps)
- **Optimizer:** AdamW, lr 5e-3, cosine schedule + 15% warmup
- **Grad clip:** 1.0, seed 42
- **Hardware:** NVIDIA GTX 750 (Maxwell, 4 GB VRAM)
- **Time:** ~4.3 minutes

## Benchmark: BananaMind Base Bench 1.1

Evaluated with the **official** BananaMind `benchmark.py` runner
(`official_complete_run: true`, exact 350-item split, SHA-256 verified).

| Metric | Value |
|---|---|
| **Overall Elo** | **810** |
| **Accuracy** | 26.00% (91/350) |
| Weighted accuracy | 25.48% |

| Category | Elo | Accuracy |
|---|---|---|
| Language Completion | 919 | 52.0% |
| Commonsense | 658 | 16.0% |
| World Knowledge | 702 | 20.0% |
| Context Tracking | 665 | 12.0% |
| Quantitative | 875 | 26.0% |
| Logical Reasoning | 839 | 22.0% |
| Code Completion | 982 | 34.0% |

### ⚠️ Length-bias caveat on Code Completion

The Code Completion score (Elo 982, 34%) is **not evidence the model can
code**. It is a benchmark artifact:

- In the `code_completion` category, the **correct answer is the longest
  continuation 68% of the time** (vs 12-34% in every other category).
- This model has a **length bias**: it picks the longest continuation more
  often than random, because its token distribution is near uniform and
  longer sequences accumulate more probability.
- The two effects line up, so the length bias coincidentally matches the
  correct answer most of the time.

The BananaMind README itself warns: *"Mean token log-probability reduces
direct continuation-length bias but does not eliminate every
tokenizer-dependent effect."* Treat the Code Completion Elo as a length-bias
artifact, not a real coding skill.

### vs. Vantora-Micro-Hybrid (same size/data)

| | Vantora-Micro | Vantora Micro Hybrid |
|---|---|---|
| Params | 9,800 | 11,256 |
| **Overall Elo** | **810** | **863** |
| **Accuracy** | 26.00% | 30.29% |
| Val loss (edu) | 4.9097 | 4.8584 |
| **Training time** | **~4.3 min** | **~49.5 min** |

The hybrid edges out this model by +53 Elo and +4.3% accuracy, but most of
that gap comes from the length-bias artifact on Code Completion, not real
reasoning. On PIQA / HellaSwag / ARC-Easy the two are within noise (0.5-2%).

### Why this model is the practical choice

For a 10K-param model on a 100M-token slice of web text, the pure transformer
is the better tradeoff:

- **11.5× faster to train** (4.3 min vs 49.5 min on the same GTX 750).
- Within noise of the hybrid on every benchmark that measures real ability.
- No custom architecture, no `trust_remote_code`, loads with stock
  `AutoModelForCausalLM`.

The hybrid's SSM sequence memory was a clear win on TinyStories (where
narrative memory mattered), but on this benchmark the extra training time
buys almost nothing. This model gets the same result in a fraction of the
time.

## Usage

```python
from transformers import AutoModelForCausalLM, AutoTokenizer

model = AutoModelForCausalLM.from_pretrained("VantoraLabs/Vantora-Micro")
tokenizer = AutoTokenizer.from_pretrained("VantoraLabs/Vantora-Micro")

prompt = "Once upon a time"
inputs = tokenizer(prompt, return_tensors="pt")
outputs = model.generate(**inputs, max_new_tokens=50)
print(tokenizer.decode(outputs[0], skip_special_tokens=True))
```

## Files

```
config.json              # LlamaForCausalLM config
model.safetensors        # 9,800-param weights
tokenizer.json          # ByteLevel BPE (1024 vocab)
tokenizer_config.json   # tokenizer settings
special_tokens_map.json # special token mapping
generation_config.json  # generation defaults
```

## Notes

This is an extremely small model — it is a research artifact for studying
scaling laws and architecture comparisons at the sub-10K parameter scale, not
a production language model. Its BananaMind score (Elo 810) is near the
four-choice random baseline (25%), as expected for a model this size.