---
language:
- en
license: apache-2.0
base_model: Qwen/Qwen2.5-3B-Instruct
tags:
- text-generation
- transformers
- safetensors
- gguf
- qwen2
- unsloth
- lora
- llama.cpp
- reasoning
- distillation
- conversational
datasets:
- EphAsad/QWENMillenium-SF
- EphAsad/Phi4Millennium-SF
- EphAsad/MistralMillenium-SF
- Modotte/CodeX-2M-Thinking
- Jackrong/Kimi-K2.5-Reasoning-1M-Cleaned
- WithinUsAI/MiniMax_M2.7_Distilled_5k
- tuanha1305/DeepSeek-R1-Distill
- open-r1/OpenThoughts-114k-math
- flytech/python-codes-25k
- FreedomIntelligence/medical-o1-reasoning-SFT
- Jackrong/Claude-opus-4.7-TraceInversion-5000x
pipeline_tag: text-generation
model-index:
- name: EphAsad/Atem-3B
  results:
  - task:
      type: text-generation
    dataset:
      name: ARC-Challenge
      type: allenai/ai2_arc
      config: ARC-Challenge
      split: test
    metrics:
    - type: acc_norm
      name: Accuracy (normalised)
      value: 0.480
      verified: false
  - task:
      type: text-generation
    dataset:
      name: GSM8K
      type: openai/gsm8k
      config: main
      split: test
    metrics:
    - type: exact_match
      name: Exact Match (flexible-extract, 5-shot)
      value: 0.647
      verified: false
  - task:
      type: text-generation
    dataset:
      name: HellaSwag
      type: Rowan/hellaswag
      split: validation
    metrics:
    - type: acc_norm
      name: Accuracy (normalised)
      value: 0.704
      verified: false
---

![Atem Logo](https://huggingface.co/EphAsad/Atem-3B/resolve/main/Logo.png)

# Atem-3B

*Ancient logic. Modern intelligence.*

The 3B foundation model of the Atem series — direct reasoning at scale.

![Base Model](https://img.shields.io/badge/Base-Qwen2.5--3B--Instruct-blue)
![Stage](https://img.shields.io/badge/Stage-1%20SFT-purple)
![Parameters](https://img.shields.io/badge/Parameters-3B-orange)
![License](https://img.shields.io/badge/License-Apache%202.0-green)

---

## Overview

Atem-3B is the first release in the 3B branch of the Atem model series — a Stage 1 supervised fine-tune on Qwen2.5-3B-Instruct across approximately 120,000 training examples spanning mathematics, code, reasoning, and general instruction following.

Where the 1.5B Atem line demonstrated that a small model could be meaningfully improved through careful data curation, Atem-3B applies the same methodology at twice the parameter count. The 3B base provides a stronger foundation — particularly for mathematical reasoning and structured generation — while the training corpus prioritises quality and diversity over volume.

**Design philosophy:** Think tags were stripped from all training data during preprocessing. Atem-3B is a direct-answer model — it does not produce `<think>` traces. The reasoning capacity of the 3B base is channelled into producing well-structured, considered responses rather than visible chain-of-thought. A CoT variant is planned for Stage 2.

---

## The Atem Series

**1.5B Series**

| Model | Stage | Capability |
|---|---|---|
| [Atem v1](https://huggingface.co/EphAsad/Atem-v1-1.5B) | Stage 1 — SFT | Fast, direct reasoning |
| [Atem-Wisdom](https://huggingface.co/EphAsad/Atem-Wisdom-1.5B) | Stage 2 — CoT | Explicit thinking traces |
| Atem-Pharaoh *(planned)* | Stage 3 — DPO/IPO | Preference-aligned reasoning |

**3B Series**

| Model | Stage | Capability |
|---|---|---|
| **Atem-3B** | Stage 1 — SFT | Direct reasoning at 3B scale |
| **Atem-3B-Pharaoh** | Stage 2 — CoT | Explicit thinking traces |

---

## Model Details

| Property | Value |
|---|---|
| **Base model** | Qwen/Qwen2.5-3B-Instruct |
| **Training method** | LoRA SFT — Stage 1 (think tags stripped) |
| **LoRA config** | r=32, alpha=64, dropout=0.05 |
| **Parameters** | ~3.09B |
| **Trainable parameters** | 59,867,136 (1.90%) |
| **Training records** | 120,043 (after token length filtering) |
| **Epochs** | 1 |
| **Final val loss** | 0.8384 |
| **Hardware** | NVIDIA A100-SXM4-80GB |
| **Max sequence length** | 4,096 tokens |
| **Precision** | bfloat16 |
| **License** | Apache 2.0 |

---

## Output Format

Atem-3B produces direct, structured responses. Think tags were stripped from all training data during preprocessing — the model was trained exclusively on clean outputs with no chain-of-thought traces.

```
[Direct response — reasoned, structured, no <think> tags]
```

This is a deliberate Stage 1 design choice. A chain-of-thought variant exposing explicit reasoning traces is planned as Stage 2.

---

## Training Data

Stage 1 training used approximately 120,000 examples drawn from eleven sources. All reasoning traces (`<think>...</think>` blocks) were stripped prior to training. Records shorter than 20 characters after stripping were excluded.

| Dataset | Count | Focus |
|---|---|---|
| Modotte/CodeX-2M-Thinking | 40,000 | Code (think tags stripped) |
| Jackrong/Kimi-K2.5-Reasoning-1M-Cleaned | 23,000 | General reasoning (English filtered) |
| open-r1/OpenThoughts-114k-math | 10,000 | Mathematics (correct only) |
| flytech/python-codes-25k | 10,000 | Python code |
| FreedomIntelligence/medical-o1-reasoning-SFT | 10,000 | Medical reasoning |
| tuanha1305/DeepSeek-R1-Distill | 9,000 | Reasoning distillation |
| EphAsad/QWENMillenium-SF | 5,000 | General instruction |
| EphAsad/MistralMillenium-SF | 5,000 | General instruction |
| WithinUsAI/MiniMax_M2.7_Distilled_5k | 5,000 | Mixed reasoning |
| Jackrong/Claude-opus-4.7-TraceInversion-5000x | 4,761 | Inverted reasoning |
| EphAsad/Phi4Millennium-SF | 2,932 | General instruction |

Chinese-language records from Kimi K2.5 were filtered using an ASCII character ratio threshold before inclusion. OpenThoughts-114k-math was filtered to `correct == True` examples only.

**Loss curve:**

| Step | Train Loss | Val Loss |
|---|---|---|
| 200 | 0.9236 | 0.9011 |
| 400 | 0.9200 | 0.8796 |
| 600 | 0.8591 | 0.8685 |
| 800 | 0.8837 | 0.8585 |
| 1000 | 0.8455 | 0.8507 |
| 1200 | 0.8359 | 0.8453 |
| 1400 | 0.8240 | 0.8413 |
| 1600 | 0.8626 | 0.8391 |
| 1800 | 0.8940 | 0.8384 |
| 1876 (final) | **0.8702** | **0.8384** |

Validation loss descends steadily throughout the full run with no overfitting signal.

---

## Evaluation

### Benchmark Results

Evaluated using lm-evaluation-harness via the Python API under identical conditions for both models. ARC-Challenge and HellaSwag use zero-shot normalised accuracy; GSM8K uses 5-shot. Both models evaluated at 4-bit quantisation on the same A100-SXM4-80GB in torch.float16.

| Task | Base (3B) | Atem-3B | Delta |
|---|---|---|---|
| ARC-Challenge | 48.1% | 48.0% | -0.1% — |
| GSM8K (strict-match) | 2.1% | 37.1% | +35.0% |
| GSM8K (flexible-extract) | 62.4% | **64.7%** | +2.3% ✓ |
| HellaSwag | 73.5% | 70.4% | -3.0% ⚠ |

**Note on GSM8K:** lm_eval's strict-match filter uses a `#### number` regex that only fires when the model produces that exact token sequence. The base Qwen2.5-3B-Instruct solves problems correctly but formats answers conversationally, yielding 2.1% strict-match against a 62.4% flexible-extract — the latter being the accurate measure of base model mathematical capability. Atem-3B's training on math distillation datasets reinforced structured answer termination, producing 37.1% strict-match. The meaningful comparison is flexible-extract: **62.4% → 64.7% (+2.3%)** — a genuine but modest improvement. The strict-match delta is a formatting artefact, not a 35-point gain in mathematical reasoning ability.

**Note on HellaSwag:** The -3.0% regression is a common pattern when fine-tuning instruct models on structured reasoning and task-completion data. HellaSwag tests commonsense sentence completion in a multiple-choice format; training on problem-solving corpora shifts the model's distribution away from the casual, predictive register that HellaSwag measures. This is a known trade-off, not an indicator of general capability loss.

---

## Usage

### Transformers

```python
from transformers import AutoModelForCausalLM, AutoTokenizer
import torch

model_name = "EphAsad/Atem-3B"

tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    torch_dtype=torch.bfloat16,
    device_map="auto"
)

messages = [
    {
        "role": "user",
        "content": "Explain the difference between a process and a thread."
    }
]

inputs = tokenizer.apply_chat_template(
    messages,
    tokenize=True,
    add_generation_prompt=True,
    return_tensors="pt"
).to(model.device)

with torch.no_grad():
    output = model.generate(
        input_ids=inputs,
        max_new_tokens=1024,
        temperature=0.7,
        top_p=0.9,
        repetition_penalty=1.1,
        do_sample=True,
    )

response = tokenizer.decode(
    output[0][inputs.shape[1]:],
    skip_special_tokens=True
)
print(response)
```

### Unsloth (faster inference)

```python
from unsloth import FastLanguageModel
import torch

model, tokenizer = FastLanguageModel.from_pretrained(
    model_name="EphAsad/Atem-3B",
    max_seq_length=4096,
    dtype=torch.bfloat16,
    load_in_4bit=True,
)
FastLanguageModel.for_inference(model)

messages = [
    {
        "role": "user",
        "content": "Write a Python function to find all prime numbers up to n."
    }
]

inputs = tokenizer.apply_chat_template(
    messages,
    tokenize=True,
    add_generation_prompt=True,
    return_tensors="pt"
).to("cuda")

with torch.no_grad():
    output = model.generate(
        input_ids=inputs,
        max_new_tokens=1024,
        temperature=0.7,
        top_p=0.9,
        do_sample=True,
    )

print(tokenizer.decode(output[0][inputs.shape[1]:], skip_special_tokens=True))
```

### Ollama

```bash
# Recommended — best speed/quality balance
ollama run hf.co/EphAsad/Atem-3B:Q4_K_M

# Higher quality
ollama run hf.co/EphAsad/Atem-3B:Q5_K_M

# Near-lossless
ollama run hf.co/EphAsad/Atem-3B:Q8_0
```

### llama.cpp

```bash
llama-server -hf EphAsad/Atem-3B:Q4_K_M
```

### Available Files

| File | Size | Description |
|---|---|---|
| `model-00001-of-00002.safetensors` + `model-00002-of-00002.safetensors` | ~6.2 GB | Full bfloat16 weights |
| `Atem-3b.Q4_K_M.gguf` | ~1.93 GB | 4-bit — recommended |
| `Atem-3b.Q5_K_M.gguf` | ~2.22 GB | 5-bit |
| `Atem-3b.Q8_0.gguf` | ~3.29 GB | 8-bit — near-lossless |

### System Prompt

Atem-3B's identity is baked into the chat template and activates without an explicit system message. To override manually:

```
You are Atem, a precise and analytical reasoning assistant. You approach
every problem methodically — identifying core concepts, reasoning step by
step, and arriving at well-supported conclusions. You show your thinking
clearly and are thorough, direct, and intellectually honest.
```

---

## Roadmap

| Stage | Status | Description |
|---|---|---|
| Stage 1 — SFT | ✅ Complete | **Atem-3B — this model** |
| Stage 2 — CoT SFT | 🔄 Planned | Atem-3B-Wisdom — chain-of-thought traces |
| Stage 3 — DPO/IPO | 🔄 Planned | Atem-3B-Pharaoh — preference-aligned reasoning |

---

## Citation

```bibtex
@misc{atem_3b_2026,
  author       = {Asad, Zain},
  title        = {Atem-3B: A 3B Direct-Reasoning Model via Stage 1 SFT},
  year         = {2026},
  publisher    = {HuggingFace},
  howpublished = {\url{https://huggingface.co/EphAsad/Atem-3B}},
}
```

---

## License

Released under the [Apache 2.0 License](https://www.apache.org/licenses/LICENSE-2.0), consistent with the base model (Qwen2.5-3B-Instruct).

---

Built independently by [EphAsad](https://huggingface.co/EphAsad)