# AWQ: Activation-aware Weight Quantization for LLM Compression and Acceleration [[Paper](https://arxiv.org/abs/2306.00978)]

**Efficient and accurate** low-bit weight quantization (INT3/4) for LLMs, supporting **instruction-tuned** models and **multi-modal** LMs. 

![overview](figures/overview.png)

The current release supports: 

- AWQ search for accurate quantization. 
- Pre-computed AWQ model zoo for LLMs (LLaMA, OPT, Vicuna, LLaVA; load to generate quantized weights).
- Memory-efficient 4-bit Linear in PyTorch.
- Efficient CUDA kernel implementation for fast inference (support context and decoding stage).
- Examples on 4-bit inference of an instruction-tuned model (Vicuna) and mult-modal LM (LLaVA).

## Contents

- [Install](#install)
- [AWQ Model Zoo](#awq-model-zoo)
- [Examples](#examples)
- [Usage](#usage)
- [Reference](#reference)

## Install

1. Clone this repository and navigate to AWQ folder
```
git clone https://github.com/mit-han-lab/llm-awq
cd llm-awq
```

2. Install Package
```
conda create -n awq python=3.10 -y
conda activate awq
pip install --upgrade pip  # enable PEP 660 support
pip install -e .
```

3. Install kernel implementation
```
cd awq/kernels
python setup.py install
```

## AWQ Model Zoo

We provide pre-computed AWQ search results for multiple model families, including LLaMA, OPT, Vicuna, and LLaVA. To get the pre-computed AWQ search results, run:

```bash
# git lfs install  # install git lfs if not already
git clone https://huggingface.co/datasets/mit-han-lab/awq-model-zoo awq_cache
```

The detailed support list:

| Models | Sizes                       | INT4-g128 | INT3-g128 |
| ------ | --------------------------- | --------- | --------- |
| LLaMA  | 7B/13B/30B/65B              | ✅         | ✅         |
| OPT    | 125m/1.3B/2.7B/6.7B/13B/30B | ✅         | ✅         |
| Vicuna | 7B/13B                      | ✅         |           |
| LLaVA  | 13B                         | ✅         |           |

## Examples

AWQ can be easily applied to various LMs thanks to its good generalization, including instruction-tuned models and multi-modal LMs. It provides an easy-to-use tool to reduce the serving cost of LLMs.

Here we provide two examples of AWQ application: Vicuna-7B (chatbot) and LLaVA-13B (visual reasoning) under `./examples` directory. AWQ can easily reduce the GPU memory of model serving and speed up token generation. It provides accurate quantization, providing reasoning outputs. You should be able to observe **memory savings** when running the models with 4-bit weights. 

Note that we perform AWQ using only textual calibration data, depsite we are running on multi-modal input. Please refer to `./examples` for details.

![overview](figures/example_vis.jpg)

## Usage

We provide several sample script to run AWQ (please refer to `./scripts`). We use OPT-6.7B as an example.

1. Perform AWQ search and save search results (we already did it for you):
```bash
python -m awq.entry --model_path /PATH/TO/OPT/opt-6.7b \
    --w_bit 4 --q_group_size 128 \
    --run_awq --dump_awq awq_cache/opt-6.7b-w4-g128.pt
```

2. Evaluate the AWQ quantize model on WikiText-2 (simulated pseudo quantization)
```bash
python -m awq.entry --model_path /PATH/TO/OPT/opt-6.7b \
    --tasks wikitext \
    --w_bit 4 --q_group_size 128 \
    --load_awq awq_cache/opt-6.7b-w4-g128.pt \
    --q_backend fake
```

3. Generate real quantized weights (INT4)
```bash
mkdir quant_cache
python -m awq.entry --model_path /PATH/TO/OPT/opt-6.7b \
    --w_bit 4 --q_group_size 128 \
    --load_awq awq_cache/opt-6.7b-w4-g128.pt \
    --q_backend real --dump_quant quant_cache/opt-6.7b-w4-g128-awq.pt
```

4. Load and evaluate the real quantized model (now you can see smaller gpu memory usage)
```bash
python -m awq.entry --model_path /PATH/TO/OPT/opt-6.7b \
    --tasks wikitext \
    --w_bit 4 --q_group_size 128 \
    --load_quant quant_cache/opt-6.7b-w4-g128-awq.pt
```

## Reference

If you find AWQ useful or relevant to your research, please kindly cite our paper:

```
@article{lin2023awq,
  title={AWQ: Activation-aware Weight Quantization for LLM Compression and Acceleration},
  author={Lin, Ji and Tang, Jiaming and Tang, Haotian and Yang, Shang and Dang, Xingyu and Han, Song},
  journal={arXiv},
  year={2023}
}
```

## Related Projects

[SmoothQuant: Accurate and Efficient Post-Training Quantization for Large Language Models](https://github.com/mit-han-lab/smoothquant)

[GPTQ: Accurate Post-training Compression for Generative Pretrained Transformers](https://arxiv.org/abs/2210.17323)

[Vicuna and FastChat](https://github.com/lm-sys/FastChat#readme)

[LLaVA: Large Language and Vision Assistant](https://github.com/haotian-liu/LLaVA)