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README.md
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license: apache-2.0
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---
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license: apache-2.0
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---
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# Llama 3.2 1B MLA - Multi-head Latent Attention Model
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This repository contains a version of Llama 3.2 1B converted to use Multi-head Latent Attention (MLA) instead of Group Query Attention (GQA).
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## Model Details
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- **Base Model**: [Meta-Llama-3.2-1B](https://huggingface.co/meta-llama/Llama-3.2-1B)
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- **Attention Mechanism**: Multi-head Latent Attention (MLA)
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- **Performance Improvement**: Approximately 70% faster inference than GQA with the same KV cache size
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## What is MLA?
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Multi-head Latent Attention (MLA) is an attention mechanism introduced in the DeepSeek-V2 paper and further explored in the [TransMLA paper](https://arxiv.org/abs/2502.07864). MLA uses low-rank factorization to compress Key (K) and Value (V) representations during attention, significantly reducing the KV cache size while maintaining or even improving model expressivity.
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Unlike Group Query Attention (GQA), which simply reduces the number of KV heads, MLA maintains the expressivity of having unique K and V representations for each query head by using factorized projection matrices.
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## Advantages over GQA
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- **Same KV Cache Size**: MLA maintains the same KV cache size as GQA
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- **Greater Expressivity**: Each Q head can have its own K and V representation (unlike GQA)
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- **Better Performance**: Significantly faster generation due to better memory utilization
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- **No Retraining Required**: Conversion can be performed post-training using SVD
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## Implementation Details
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The model was converted using SVD (Singular Value Decomposition) to factorize the weight matrices. The process:
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1. Decomposes the original K and V matrices into low-rank approximations
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2. Creates compression and decompression layers that maintain the same KV cache size as GQA
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3. Preserves the original model's knowledge while improving inference efficiency
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## Usage
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```python
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from transformers import AutoModelForCausalLM, AutoTokenizer
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import torch
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# Load the model
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model = AutoModelForCausalLM.from_pretrained(
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"BarraHome/llama3.2-1b-mla",
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torch_dtype=torch.bfloat16,
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device_map="auto"
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)
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tokenizer = AutoTokenizer.from_pretrained("BarraHome/llama3.2-1b-mla")
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# Example chat prompt
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prompt = """<|begin_of_text|><|system|>
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You are a helpful, respectful, and honest assistant.
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<|user|>
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What is Multi-head Latent Attention (MLA)?
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<|assistant|>"""
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# Generate response
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inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
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outputs = model.generate(
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**inputs,
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max_new_tokens=200,
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do_sample=True,
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temperature=0.7,
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top_p=0.9
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)
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# Print response
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print(tokenizer.decode(outputs[0], skip_special_tokens=True))
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```
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## Performance Benchmarks
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When compared to the original Llama 3.2 1B model with GQA:
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- **Generation Speed**: ~70% faster (tokens per second)
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- **Memory Usage**: Same KV cache memory footprint
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- **Quality**: Maintains the same quality as the original model
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## Conversion Method
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The conversion from GQA to MLA was performed using the approach described in the [TransMLA: Multi-Head Latent Attention Is All You Need](https://arxiv.org/abs/2502.07864) paper. The key insight is that GQA can always be represented by MLA with the same KV cache overhead, but MLA offers greater expressivity.
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## Citation
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If you use this model in your research or projects, please cite:
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```bibtex
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@misc{ferrer2025llama32mla,
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title={Llama 3.2 1B MLA - Multi-head Latent Attention},
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author={Ferrer, Alberto},
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year={2025},
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howpublished={\url{https://huggingface.co/BarraHome/llama3.2-1b-mla}}
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}
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```
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Also consider citing the underlying TransMLA methodology:
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```bibtex
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@article{meng2025transmla,
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title={TransMLA: Multi-Head Latent Attention Is All You Need},
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author={Meng, Fanxu and Yao, Zengwei and Zhang, Muhan},
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journal={arXiv preprint arXiv:2502.07864},
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year={2025}
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}
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```
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## License
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This model is subject to the same license as the original Meta-Llama-3.2-1B model. Please refer to Meta's licensing terms for usage restrictions.
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## Acknowledgements
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- Developed by Alberto Ferrer (BarraHome)
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- Thanks to the authors of the TransMLA paper for their insights on converting GQA to MLA
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- Thanks to DeepSeek AI for the original introduction of MLA in their DeepSeek-V2 model
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- Thanks to Meta for releasing the Llama 3.2 models
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