Model Overview
- Model Architecture: Qwen3_5MoeForCausalLM
- Source Model: Qwen3.6-35B-A3B
- Supported Hardware: AMD EPYC (CPU inference)
- Preferred Operating System: Linux
- Inference Engine: vLLM v0.26.0
- Quantization Framework: LLM Compressor v0.12.0
- Quantization Method: 4-bit Weight-Only Quantization (W4A16)
- Compatible Stack:
- ZenDNN v6.1.0
- ZenTorch v2.11.0.3
- PyTorch v2.11.0
- LLM Compressor v0.12.0
- vLLM v0.26.0
This is a quantized version of Qwen3.6-35B-A3B created by AMD using LLM Compressor (compressed-tensors) for ZenDNN-optimized CPU inference.
Quantization
The model was quantized from Qwen3.6-35B-A3B using LLM Compressor via the GPTQ algorithm. This reduces the model weights from 67.0 GiB to 18.1 GiB on disk (~73% reduction).
- Method: 4-bit Weight-Only Quantization (W4A16)
- Config:
compressed-tensors, num_bits=4, type=int, symmetric=true, group_size=128
- Weights: INT4, symmetric, group-wise (
group_size=128, actorder=static), stored as pack-quantized
- Activations: BF16 (unquantized)
- Group Size: 128, auto-selected as the largest of 128/64/32 that divides every quantizable weight's column count
- Calibration: 128 examples from HuggingFaceH4/ultrachat_200k at a max sequence length of 2048
- Kept in BF16: the MoE router (
mlp.gate), lm_head, embed_tokens, and the layer norms. The 256 routed experts, the shared expert, and the linear-attention projections are all quantized, which is why the reduction is close to the 75% ideal for INT4.
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer
from datasets import load_dataset
from llmcompressor import oneshot
from llmcompressor.modifiers.quantization.gptq import GPTQModifier
model_id = "Qwen/Qwen3.6-35B-A3B"
save_dir = "./Qwen3.6-35B-A3B-w4a16-llmcompressor-v0.12.0"
CALIB_SIZE = 128
MAX_SEQ_LENGTH = 2048
model = AutoModelForCausalLM.from_pretrained(
model_id,
device_map="cpu",
dtype=torch.bfloat16,
trust_remote_code=True,
)
tokenizer = AutoTokenizer.from_pretrained(model_id, trust_remote_code=True)
ds = load_dataset("HuggingFaceH4/ultrachat_200k", split=f"train_sft[:{CALIB_SIZE}]")
ds = ds.map(
lambda example: {"text": "\n".join(m["content"] for m in example["messages"] if m["content"])},
remove_columns=ds.column_names,
)
recipe = GPTQModifier(
targets="Linear",
scheme="W4A16",
ignore=[
"lm_head",
r"re:.*\.router$",
r"re:.*\.router\..*",
r"re:.*\.gate$",
r"re:.*\.mlp\.gate$",
],
)
oneshot(
model=model,
dataset=ds,
recipe=recipe,
max_seq_length=MAX_SEQ_LENGTH,
processor=tokenizer,
)
model.save_pretrained(save_dir, save_compressed=True)
tokenizer.save_pretrained(save_dir)
inputs = tokenizer("What are we having for dinner?", return_tensors="pt")
output = model.generate(**inputs, max_new_tokens=30)
print(tokenizer.decode(output[0], skip_special_tokens=True))
Run end to end with the driver script:
numactl --physcpubind=0-95 python llm_compressor_quantize_and_run.py \
--model_id Qwen/Qwen3.6-35B-A3B \
--save_dir ./Qwen3.6-35B-A3B-w4a16-llmcompressor-v0.12.0 \
--recipe gptq \
--scheme W4A16 \
--run
Quick Start
Use with vLLM
from vllm import LLM, SamplingParams
model = LLM(
model="amd/Qwen3.6-35B-A3B-w4a16-llmcompressor-v0.12.0",
dtype="bfloat16",
)
sampling_params = SamplingParams(temperature=0.7, max_tokens=256)
outputs = model.generate(["Hello, how are you?"], sampling_params)
print(outputs[0].outputs[0].text)
Requirements
torch==2.11.0
zentorch==2.11.0.3
vllm==0.26.0
llmcompressor==0.12.0
OpenMP Setup
For optimal performance, set LD_PRELOAD with libomp.so (LLVM OpenMP) or libiomp5.so (Intel OpenMP):
# Using LLVM OpenMP (llvmopenmp)
export LD_PRELOAD=$(find /path/to/env -name "libomp.so" | head -1)
# Or using Intel OpenMP (libiomp)
export LD_PRELOAD=$(find /path/to/env -name "libiomp5.so" | head -1)
Note: Set LD_PRELOAD before launching vLLM or any inference script.
Evaluation
The model was evaluated against the BF16 (unquantized) baseline on standard benchmarks using lm-evaluation-harness with the vLLM engine.
Table with columns: Benchmark, BF16 Baseline, W4A16 (this model), Recovery| Benchmark | BF16 Baseline | W4A16 (this model) | Recovery |
|---|
| GSM8K (5-shot) | 0.9651 | 0.9636 | 99.84% |
Evaluation results will be updated after benchmarking.
Evaluation Command
lm_eval \
--model vllm \
--model_args pretrained=amd/Qwen3.6-35B-A3B-w4a16-llmcompressor,tokenizer=Qwen/Qwen3.6-35B-A3B,dtype=bfloat16,max_model_len=4096,enable_thinking=False \
--tasks gsm8k \
--batch_size auto \
--trust_remote_code \
--num_fewshot 5 \
--apply_chat_template \
--log_samples \
--gen_kwargs "max_gen_toks=2048" \
--output_path .
Limitations
- Version Lock: This model is compatible with ZenDNN v6.1.0 / ZenTorch v2.11.0.3 / PyTorch v2.11.0. It may not load correctly on other versions.
- CPU Only: This model is optimized for AMD EPYC CPU inference via ZenDNN. It is not intended for GPU inference.
- Text-Only Checkpoint: The model was loaded through
AutoModelForCausalLM during quantization, so the saved config is the text-only Qwen3_5MoeForCausalLM variant. The vision path of the source model is not carried over.
- Reasoning Model: Qwen3.6 emits thinking traces by default. Evaluate with
enable_thinking=False (and a generous max_gen_toks) so answer extraction stays comparable to the BF16 baseline.
- Accuracy Trade-off: 4-bit weight-only quantization is more aggressive than INT8 and trades some accuracy for a ~73% smaller memory footprint.
License
This model is distributed under the same license as the source model. See the LICENSE file for details.
Modifications copyright (c) 2026 Advanced Micro Devices, Inc. All rights reserved.