Qwen3.6-35B-A3B-int4-AutoRound

Qwen3.6-35B-A3B — INT4 AutoRound Quantization

4-bit quantization of Qwen/Qwen3.6-35B-A3B produced with spark-auto-round.

Qwen3.6-35B-A3B is a Mixture-of-Experts model with 35B total parameters and ~3B active parameters per forward pass (256 experts, 8 active). It features a hybrid attention architecture (linear + full attention every 4 layers) and a 262K token context window.

Quantization Details

MLP gate layers and shared expert gate layers are kept in FP16 to preserve routing quality.

Quality Report

Quantized with AutoRound's sensitivity-based optimization. All 40 transformer blocks were evaluated:

All layers maintain cosine similarity > 0.98 vs the original. Warnings are concentrated in the deeper layers (23–37), which is typical for MoE models at 4-bit.

Usage

from transformers import AutoModelForCausalLM, AutoTokenizer

model_name = "cyburn/Qwen3.6-35B-A3B-int4-AutoRound"

tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    device_map="auto",
)

messages = [{"role": "user", "content": "Write a Python function to compute Fibonacci numbers."}]
text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = tokenizer(text, return_tensors="pt").to(model.device)

outputs = model.generate(**inputs, max_new_tokens=512, temperature=1.0, top_k=20, top_p=0.95)
print(tokenizer.decode(outputs[0][inputs.input_ids.shape[1]:], skip_special_tokens=True))

Model Architecture

• Architecture: Qwen3.5 MoE (hybrid linear + full attention)
• Total parameters: ~35B
• Active parameters: ~3B per token
• Experts: 256 total, 8 active per token
• Layers: 40 (linear attention every 3 layers, full attention every 4th)
• Context length: 262,144 tokens
• Vocabulary: 248,320 tokens

Hardware Requirements

The quantized model requires approximately ~19.5 GB of VRAM/RAM. A single 24 GB GPU (e.g., RTX 3090/4090) or two 12 GB GPUs with device_map="auto" are sufficient.

Quantization Command

auto-round \
  --model Qwen/Qwen3.6-35B-A3B \
  --batch_size 8 \
  --iters 1000 \
  --nsamples 512 \
  --seqlen 2048 \
  --dataset opencode-instruct \
  --output_dir ./models/Qwen3.6-35B-A3B-int4-AutoRound

Credits

• Base model: Qwen/Qwen3.6-35B-A3B by Alibaba Cloud
• Quantization tool: spark-auto-round — a GB10-optimized fork of Intel's auto-round, tuned for DGX Spark / GB10 unified memory hardware