GLM-4.6-AWQ - Optimized 4-bit Quantization for Production Deployment

High-performance AWQ quantization of ZHIPU AI's GLM-4.6 (357B MoE) optimized for vLLM inference

📊 Model Overview

This is a professionally quantized 4-bit AWQ version of Z.ai's GLM-4.6 optimized for high-throughput production deployment with vLLM.

• Base Model: GLM-4.6 (357B parameters, 160 experts MoE)
• Model Size: 176 GB (39 safetensors files)
• License: MIT (inherited from base model)
• Quantization: AWQ 4-bit with group size 128
• Active Parameters: 28.72B per token (8 of 160 experts)
• Quantization Framework: llmcompressor 0.8.1.dev0
• Optimization: Marlin kernels for NVIDIA GPUs
• Context Length: Up to 200K tokens (131K recommended for optimal performance)
• Languages: English, Chinese

🚀 Performance Benchmarks

Tested on 4× NVIDIA RTX PRO 6000 Blackwell Max-Q (96GB each, 384GB total VRAM):

Performance Characteristics

• Memory Bandwidth Efficiency: 50.3% (excellent for MoE models)
• Theoretical Maximum: 130 tok/s (memory bandwidth bound)
• Aggregate Bandwidth: 1.7 TB/s effective (4× RTX PRO 6000 Blackwell Max-Q)
• Actual vs Theoretical: Typical for sparse MoE architecture

Why AWQ Over Other Quantizations?

Research shows: AWQ has ~1 point MMLU drop while GPTQ has ~2 points. AWQ performance is indistinguishable from full BF16 on real-world benchmarks.

💾 VRAM Requirements

Minimum Requirements (Expert Parallelism)

• Model Download Size: 176 GB
• 4× GPUs with 48GB+ VRAM each (192GB total minimum)
• Recommended: 4× 80GB GPUs or 4× 96GB GPUs
• Memory Type: HBM2e/HBM3/HBM3e for best performance
• Disk Space: 180+ GB for model storage

Supported Configurations

🛠️ Installation & Usage

Prerequisites

pip install vllm>=0.11.0
# Or install from source for latest features
git clone https://github.com/vllm-project/vllm.git
cd vllm && pip install -e .

Quick Start with vLLM

Recommended Configuration (Expert Parallelism for Multi-Model Deployment):

vllm serve <model_path> \
  --tensor-parallel-size 4 \
  --enable-expert-parallel \
  --tool-call-parser glm45 \
  --reasoning-parser glm45 \
  --enable-auto-tool-choice \
  --served-model-name glm-4.6-awq \
  --max-model-len 131072 \
  --gpu-memory-utilization 0.9 \
  --trust-remote-code \
  --port 8000

Maximum Speed Configuration (Single Model):

vllm serve <model_path> \
  --tensor-parallel-size 4 \
  --tool-call-parser glm45 \
  --reasoning-parser glm45 \
  --enable-auto-tool-choice \
  --served-model-name glm-4.6-awq \
  --max-model-len 131072 \
  --gpu-memory-utilization 0.9 \
  --trust-remote-code \
  --port 8000

Python API Usage

from vllm import LLM, SamplingParams

# Initialize with expert parallelism (saves VRAM)
llm = LLM(
    model="path/to/GLM-4.6-AWQ",
    tensor_parallel_size=4,
    enable_expert_parallel=True,
    max_model_len=131072,
    trust_remote_code=True,
    gpu_memory_utilization=0.9
)

# Disable reasoning overhead for maximum speed
prompts = [
    "Explain quantum computing in simple terms. /nothink",
    "Write a Python function to calculate Fibonacci numbers. /nothink"
]

sampling_params = SamplingParams(
    temperature=0.7,
    top_p=0.95,
    max_tokens=400
)

outputs = llm.generate(prompts, sampling_params)
for output in outputs:
    print(output.outputs[0].text)

OpenAI-Compatible API

from openai import OpenAI

client = OpenAI(
    base_url="http://localhost:8000/v1",
    api_key="dummy"  # vLLM doesn't require authentication
)

response = client.chat.completions.create(
    model="glm-4.6-awq",
    messages=[
        {"role": "user", "content": "Explain quantum computing /nothink"}
    ],
    max_tokens=400,
    temperature=0.7
)

print(response.choices[0].message.content)

🔧 Quantization Details

Technical Specifications

• Method: Activation-Aware Weight Quantization (AWQ)
• Precision: 4-bit signed integers
• Group Size: 128 (optimal balance of speed/accuracy)
• Calibration Dataset: neuralmagic/LLM_compression_calibration (512 samples)
• Format: Compressed-tensors with Marlin kernel support
• Kernel: MarlinLinearKernel + CompressedTensorsWNA16MarlinMoEMethod

What Was Quantized?

• ✅ All 92 transformer decoder layers (layers 0-91)
• ✅ All 160 experts per layer (MoE experts)
• ✅ Attention projections (Q, K, V, O)
• ✅ MLP projections (gate, up, down)
• ❌ LM head (kept at full precision for output quality)
• ❌ MTP layer 92 (removed - incompatible with 4-bit quantization)

Note on MTP (Multi-Token Prediction): The original GLM-4.6 includes a speculative decoding layer (layer 92) for drafting multiple tokens. This layer has been intentionally removed from this quantization because:

1. 4-bit precision is insufficient for MTP to achieve acceptable draft token acceptance rates (0% acceptance observed)
2. Adds 1.92GB VRAM without providing speedup benefits
3. Research shows 8-bit or FP16 precision is required for effective MTP

Quantization Process

This model was quantized using the following configuration:

from llmcompressor import oneshot
from llmcompressor.modifiers.awq import AWQModifier
from datasets import load_dataset

# Load calibration data from Neural Magic's curated dataset
dataset = load_dataset("neuralmagic/LLM_compression_calibration", split="train")
dataset = dataset.shuffle(seed=42).select(range(512))

# Define ignore patterns and targets
ignore_patterns = [
    "lm_head",
    "model.embed_tokens",
    "re:.*input_layernorm$",
    "re:.*post_attention_layernorm$",
    "model.norm",
    "re:.*q_norm$",
    "re:.*k_norm$",
    "re:.*shared_experts.*",
    "re:.*mlp\\.gate\\.weight$",
    "re:.*mlp\\.gate\\..*bias$",
    "re:model.layers.[0-2]\\.",
]

targets = [
    "re:.*gate_proj.*",
    "re:.*up_proj.*",
    "re:.*down_proj.*",
    "re:.*k_proj.*",
    "re:.*q_proj.*",
    "re:.*v_proj.*",
    "re:.*o_proj.*",
]

# AWQ quantization recipe
recipe = [
    AWQModifier(
        ignore=ignore_patterns,
        config_groups={
            "group_0": {
                "targets": targets,
                "weights": {
                    "num_bits": 4,
                    "type": "int",
                    "symmetric": True,
                    "group_size": 128,
                    "strategy": "group",
                    "dynamic": False,
                },
                "input_activations": None,
                "output_activations": None,
                "format": None,
            }
        },
    )
]

# Apply quantization
oneshot(
    model=model,  # Pre-loaded AutoModelForCausalLM
    dataset=dataset,
    recipe=recipe,
    max_seq_length=2048,
    num_calibration_samples=512
)

⚡ Performance Optimization Tips

1. Use /nothink for Maximum Speed

GLM-4.6 includes a reasoning mode that adds thinking overhead. Disable it for ~9% speedup:

# Add /nothink to your prompts
prompt = "Your question here /nothink"

2. Enable Expert Parallelism

Distribute experts across GPUs to save VRAM for multi-model serving:

--enable-expert-parallel  # Saves ~50GB total VRAM across 4 GPUs

3. Optimize Context Length

Longer context = more KV cache memory:

--max-model-len 131072  # Recommended (vs default 202752)

4. Tune Concurrent Requests

--max-num-seqs 1  # Minimum KV cache (single request at max context)
--max-num-seqs 64  # Higher throughput (multiple concurrent requests)

5. Monitor Memory Bandwidth

This model is memory bandwidth bound. Faster GPUs see proportional speedups:

• H100 (3.35 TB/s): ~120 tok/s
• H200 NVL (4.8 TB/s): ~165 tok/s
• RTX PRO 6000 Blackwell Max-Q (1.75 TB/s): ~60 tok/s

🎯 Use Cases

Recommended Applications

• ✅ Production Chatbots: Fast, accurate responses with minimal VRAM
• ✅ Multi-Model Serving: Expert parallelism enables running multiple models
• ✅ Code Generation: High accuracy maintained vs full precision
• ✅ Reasoning Tasks: Use default mode (without /nothink)
• ✅ Long Context: Supports up to 202K tokens

Not Recommended For

• ❌ Speculative Decoding: MTP layer removed (requires 8-bit+ precision)
• ❌ Extreme Precision Tasks: Use FP8 or BF16 if accuracy is critical
• ❌ Single GPU Deployment: Requires 4× GPUs minimum

📈 Accuracy Benchmarks

AWQ quantization maintains excellent quality:

Key Finding: Research shows AWQ performs indistinguishably from BF16 on real-world benchmarks, while GPTQ shows measurable degradation due to overfitting on calibration data.

🔬 Technical Deep Dive

Architecture

• Type: Mixture of Experts (MoE) Transformer
• Total Parameters: 357B (base model specification)
• Experts: 160 routed experts per layer
• Active Experts: 8 per token (5% utilization)
• Layers: 92 decoder layers
• Heads: 96 attention heads (8 KV heads)
• Hidden Size: 5120
• Intermediate Size: 12288 (dense), 1536 (MoE)
• Vocabulary: 151,552 tokens
• Context Window: 200K tokens (original spec)

Memory Layout

Why Marlin Kernels?

Marlin is the state-of-the-art kernel for 4-bit quantized inference:

• Speed: 2-3× faster than CUDA native 4-bit
• Efficiency: Optimized for Ampere/Ada/Hopper/Blackwell architectures
• Features: Fused dequantization + GEMM operations
• Support: Integrated into vLLM for production use

🔍 Comparison to Other Models

📝 Known Limitations

1. Requires 4× GPUs: Minimum deployment configuration
2. No MTP Support: Speculative decoding layer removed
3. Memory Bandwidth Bound: Speed scales with GPU memory bandwidth
4. TP=4 Only: Tested configuration (other TP sizes may work)
5. vLLM Dependency: Optimized specifically for vLLM runtime

🐛 Troubleshooting

"KeyError: 'Linear'" Error

Run the fix script to add required config:

python fix_awq_config_for_vllm.py --model /path/to/GLM-4.6-AWQ

Out of Memory Errors

1. Enable expert parallelism: --enable-expert-parallel
2. Reduce context length: --max-model-len 65536
3. Lower GPU utilization: --gpu-memory-utilization 0.85
4. Limit concurrent requests: --max-num-seqs 1

Slow Inference

1. Check /nothink is appended to prompts
2. Verify Marlin kernels are active (check logs)
3. Monitor GPU utilization (nvidia-smi dmon)
4. Ensure NVLink is working between GPUs

📚 Citation

If you use this quantized model, please cite:

@software{glm4_awq_2025,
  title = {GLM-4.6-AWQ: Production-Optimized 4-bit Quantization},
  author = {bullpoint},
  year = {2025},
  url = {https://huggingface.co/bullpoint/GLM-4.6-AWQ}
}

@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 preprint arXiv:2306.00978},
  year={2023}
}

@software{zai2025glm46,
  title={GLM-4.6},
  author={Z.ai and ZHIPU AI},
  year={2025},
  url={https://huggingface.co/zai-org/GLM-4.6},
  license={MIT}
}

📜 License

MIT License - This quantized model inherits the MIT license from the original GLM-4.6 model.

You are free to:

• ✅ Use commercially
• ✅ Modify and distribute
• ✅ Use privately
• ✅ Sublicense

See the base model repository for full license terms.

🙏 Acknowledgments

• Z.ai for the original GLM-4.6 model
• ZHIPU AI for the GLM architecture and training
• vLLM Team for the excellent inference engine
• MIT Han Lab for the AWQ algorithm
• Neural Magic for:
  • llm-compressor quantization toolkit
  • LLM_compression_calibration calibration dataset
• Community for testing and feedback

🔧 Reproduction

Want to quantize this model yourself? See the included quantize_glm46_awq.py script for the exact quantization configuration used.

Quantization Hardware Requirements

This model was quantized on modest hardware with extensive CPU offloading:

• GPU: 1× NVIDIA RTX PRO 6000 Blackwell Max-Q (96GB GDDR7)
• RAM: 768GB DDR5
• Swap: 300GB (actively used during quantization)
• Quantization Time: ~5 hours (includes calibration, smoothing, compression, and saving)

Note: The quantization process offloads the full BF16 model (~714GB) to system RAM/swap since it exceeds available VRAM. Using 4 GPUs during quantization provides no speed benefit - the process is CPU memory-bound, not GPU-bound. The included script defaults to single-GPU mode (CUDA_VISIBLE_DEVICES=0) for optimal resource usage.

Key Settings

• Calibration dataset: neuralmagic/LLM_compression_calibration
• Samples: 512
• Sequence length: 2048 tokens
• Group size: 128
• Bits: 4 (symmetric int)
• Device map: Sequential (CPU offloading enabled)

📬 Support

For issues and questions:

• Model Issues: Open an issue on this model's repository
• vLLM Issues: vLLM GitHub
• Quantization: llm-compressor GitHub

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Status: ✅ Production Ready | Last Updated: October 2025 | Tested With: vLLM 0.11.0+