[Docs] add auto-round quantization readme (#21600)

Signed-off-by: Wenhua Cheng <wenhua.cheng@intel.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

docs/features/quantization/README.md

@@ -6,6 +6,7 @@ Contents:
 
 - [Supported Hardware](supported_hardware.md)
 - [AutoAWQ](auto_awq.md)
+- [AutoRound](auto_round.md)
 - [BitsAndBytes](bnb.md)
 - [BitBLAS](bitblas.md)
 - [GGUF](gguf.md)

docs/features/quantization/auto_round.md

+# AutoRound
+
+[AutoRound](https://github.com/intel/auto-round) is Intel’s advanced quantization algorithm designed to produce highly efficient **INT2, INT3, INT4, and INT8**
+quantized large language models—striking an optimal balance between accuracy and deployment performance.
+
+AutoRound applies weight-only quantization to transformer-based models, enabling significant memory savings and faster
+inference while maintaining near-original accuracy. It supports a wide range of hardware platforms, including **CPUs,
+Intel GPUs, HPUs, and CUDA-enabled devices**.
+
+Please refer to the [AutoRound guide](https://github.com/intel/auto-round/blob/main/docs/step_by_step.md) for more details.
+
+Key Features:
+
+✅ **AutoRound, AutoAWQ, AutoGPTQ, and GGUF** are supported
+
+✅ **10+ vision-language models (VLMs)** are supported
+
+✅ **Per-layer mixed-bit quantization** for fine-grained control
+
+✅ **RTN (Round-To-Nearest) mode** for quick quantization with slight accuracy loss
+
+✅ **Multiple quantization recipes**: best, base, and light
+
+✅ Advanced utilities such as immediate packing and support for **10+ backends**
+
+## Installation
+
+```bash
+uv pip install auto-round
+```
+
+## Quantizing a model
+
+For VLMs, please change to `auto-round-mllm` in CLI usage and `AutoRoundMLLM` in API usage.
+
+### CLI usage
+
+```bash
+auto-round \
+    --model Qwen/Qwen3-0.6B \
+    --bits 4 \
+    --group_size 128 \
+    --format "auto_round" \
+    --output_dir ./tmp_autoround
+```
+
+```bash
+auto-round \
+    --model Qwen/Qwen3-0.6B \
+    --format "gguf:q4_k_m" \
+    --output_dir ./tmp_autoround
+```
+
+### API usage
+
+```python
+from transformers import AutoModelForCausalLM, AutoTokenizer
+from auto_round import AutoRound
+
+model_name = "Qwen/Qwen3-0.6B"
+model = AutoModelForCausalLM.from_pretrained(model_name, torch_dtype="auto")
+tokenizer = AutoTokenizer.from_pretrained(model_name)
+
+bits, group_size, sym = 4, 128, True
+autoround = AutoRound(model, tokenizer, bits=bits, group_size=group_size, sym=sym)
+
+# the best accuracy, 4-5X slower, low_gpu_mem_usage could save ~20G but ~30% slower
+# autoround = AutoRound(model, tokenizer, nsamples=512, iters=1000, low_gpu_mem_usage=True, bits=bits, group_size=group_size, sym=sym)
+
+# 2-3X speedup, slight accuracy drop at W4G128
+# autoround = AutoRound(model, tokenizer, nsamples=128, iters=50, lr=5e-3, bits=bits, group_size=group_size, sym=sym )
+
+output_dir = "./tmp_autoround"
+# format= 'auto_round'(default), 'auto_gptq', 'auto_awq'
+autoround.quantize_and_save(output_dir, format="auto_round")
+```
+
+## Running a quantized model with vLLM
+
+Here is some example code to run auto-round format in vLLM:
+
+```python
+from vllm import LLM, SamplingParams
+
+prompts = [
+    "Hello, my name is",
+]
+sampling_params = SamplingParams(temperature=0.6, top_p=0.95)
+model_name = "Intel/DeepSeek-R1-0528-Qwen3-8B-int4-AutoRound"
+llm = LLM(model=model_name)
+
+outputs = llm.generate(prompts, sampling_params)
+
+for output in outputs:
+    prompt = output.prompt
+    generated_text = output.outputs[0].text
+    print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
+```
+
+# Acknowledgement
+
+Special thanks to open-source low precision libraries such as AutoGPTQ, AutoAWQ, GPTQModel, Triton, Marlin, and
+ExLLaMAV2 for providing low-precision CUDA kernels, which are leveraged in AutoRound.