| 1 | # GPTQModel |
| 2 | |
| 3 | To create a new 4-bit or 8-bit GPTQ quantized model, you can leverage [GPTQModel](https://github.com/ModelCloud/GPTQModel) from ModelCloud.AI. |
| 4 | |
| 5 | Quantization reduces the model's precision from BF16/FP16 (16-bits) to INT4 (4-bits) or INT8 (8-bits) which significantly reduces the |
| 6 | total model memory footprint while at-the-same-time increasing inference performance. |
| 7 | |
| 8 | Compatible GPTQModel quantized models can leverage the `Marlin` and `Machete` vLLM custom kernels to maximize batching |
| 9 | transactions-per-second `tps` and token-latency performance for both Ampere (A100+) and Hopper (H100+) Nvidia GPUs. |
| 10 | These two kernels are highly optimized by vLLM and NeuralMagic (now part of Redhat) to allow world-class inference performance of quantized GPTQ |
| 11 | models. |
| 12 | |
| 13 | GPTQModel is one of the few quantization toolkits in the world that allows `Dynamic` per-module quantization where different layers and/or modules within a llm model can be further optimized with custom quantization parameters. `Dynamic` quantization |
| 14 | is fully integrated into vLLM and backed up by support from the ModelCloud.AI team. Please refer to [GPTQModel readme](https://github.com/ModelCloud/GPTQModel?tab=readme-ov-file#dynamic-quantization-per-module-quantizeconfig-override) |
| 15 | for more details on this and other advanced features. |
| 16 | |
| 17 | ## Installation |
| 18 | |
| 19 | You can quantize your own models by installing [GPTQModel](https://github.com/ModelCloud/GPTQModel) or picking one of the [5000+ models on Huggingface](https://huggingface.co/models?search=gptq). |
| 20 | |
| 21 | ```bash |
| 22 | pip install -U gptqmodel --no-build-isolation -v |
| 23 | ``` |
| 24 | |
| 25 | ## Quantizing a model |
| 26 | |
| 27 | After installing GPTQModel, you are ready to quantize a model. Please refer to the [GPTQModel readme](https://github.com/ModelCloud/GPTQModel/?tab=readme-ov-file#quantization) for further details. |
| 28 | |
| 29 | Here is an example of how to quantize `meta-llama/Llama-3.2-1B-Instruct`: |
| 30 | |
| 31 | ??? code |
| 32 | |
| 33 | ```python |
| 34 | from datasets import load_dataset |
| 35 | from gptqmodel import GPTQModel, QuantizeConfig |
| 36 | |
| 37 | model_id = "meta-llama/Llama-3.2-1B-Instruct" |
| 38 | quant_path = "Llama-3.2-1B-Instruct-gptqmodel-4bit" |
| 39 | |
| 40 | calibration_dataset = load_dataset( |
| 41 | "allenai/c4", |
| 42 | data_files="en/c4-train.00001-of-01024.json.gz", |
| 43 | split="train", |
| 44 | ).select(range(1024))["text"] |
| 45 | |
| 46 | quant_config = QuantizeConfig(bits=4, group_size=128) |
| 47 | |
| 48 | model = GPTQModel.load(model_id, quant_config) |
| 49 | |
| 50 | # increase `batch_size` to match gpu/vram specs to speed up quantization |
| 51 | model.quantize(calibration_dataset, batch_size=2) |
| 52 | |
| 53 | model.save(quant_path) |
| 54 | ``` |
| 55 | |
| 56 | ## Running a quantized model with vLLM |
| 57 | |
| 58 | To run a GPTQModel quantized model with vLLM, you can use [DeepSeek-R1-Distill-Qwen-7B-gptqmodel-4bit-vortex-v2](https://huggingface.co/ModelCloud/DeepSeek-R1-Distill-Qwen-7B-gptqmodel-4bit-vortex-v2) with the following command: |
| 59 | |
| 60 | ```bash |
| 61 | python examples/deployment/llm_engine_example.py \ |
| 62 | --model ModelCloud/DeepSeek-R1-Distill-Qwen-7B-gptqmodel-4bit-vortex-v2 |
| 63 | ``` |
| 64 | |
| 65 | ## Using GPTQModel with vLLM's Python API |
| 66 | |
| 67 | GPTQModel quantized models are also supported directly through the LLM entrypoint: |
| 68 | |
| 69 | ??? code |
| 70 | |
| 71 | ```python |
| 72 | from vllm import LLM, SamplingParams |
| 73 | |
| 74 | # Sample prompts. |
| 75 | prompts = [ |
| 76 | "Hello, my name is", |
| 77 | "The president of the United States is", |
| 78 | "The capital of France is", |
| 79 | "The future of AI is", |
| 80 | ] |
| 81 | |
| 82 | # Create a sampling params object. |
| 83 | sampling_params = SamplingParams(temperature=0.6, top_p=0.9) |
| 84 | |
| 85 | # Create an LLM. |
| 86 | llm = LLM(model="ModelCloud/DeepSeek-R1-Distill-Qwen-7B-gptqmodel-4bit-vortex-v2") |
| 87 | |
| 88 | # Generate texts from the prompts. The output is a list of RequestOutput objects |
| 89 | # that contain the prompt, generated text, and other information. |
| 90 | outputs = llm.generate(prompts, sampling_params) |
| 91 | |
| 92 | # Print the outputs. |
| 93 | print("-"*50) |
| 94 | for output in outputs: |
| 95 | prompt = output.prompt |
| 96 | generated_text = output.outputs[0].text |
| 97 | print(f"Prompt: {prompt!r}\nGenerated text: {generated_text!r}") |
| 98 | print("-"*50) |
| 99 | ``` |