Welcome to Qwen36-27B-GPTQ-Pro-4Bit – a titan of reasoning and generation, elegantly squeezed into a remarkably efficient 4-bit package. It punches leagues above its weight class while keeping your VRAM happy and your inference speeds blazingly fast! Thank you Qwen team for another amazing model.

🌟 Why the "Pro"?

This isn't your average quantization. We used the GPTQ-Pro framework combined with the FOEM (First-Order Error Metric) approach. This advanced technique carefully preserves the most critical weights during the 4-bit compression process by evaluating the exact impact of quantization on the model's loss landscape.

The result?

Near-Lossless Performance: Enjoy the profound reasoning, coding prowess, and vast knowledge of a 27 Billion parameter model, but with a drastically reduced memory footprint.
Marlin Optimized: Ready out-of-the-box for Marlin kernels to deliver maximum token-per-second throughput in serving engines like vLLM.
Consumer Hardware Friendly: Fit a massive 27B powerhouse model on consumer GPUs with room to spare for massive context lengths!

This repository contains a 4-bit GPTQ-Pro quantization of unsloth/Qwen3.6-27B, produced with GPTQModel and the FOEM/GPTAQ-style quality settings used in the GPTQ-Pro project.

Source project: https://github.com/groxaxo/GPTQ-Pro

Deployment

vLLM

bash

CUDA_VISIBLE_DEVICES=0,1 vllm serve groxaxo/Qwen3.6-27B-GPTQ-Pro-4Bit \
  --dtype float16 \
  --quantization gptq_marlin \
  --disable-custom-all-reduce \
  --tensor-parallel-size 2 \
  --max-model-len 132144 \
  --reasoning-parser qwen3 \
  --enable-auto-tool-choice \
  --tool-call-parser qwen3_coder \
  --gpu-memory-utilization 0.92

Local path

bash

CUDA_VISIBLE_DEVICES=0,1 vllm serve /path/to/Qwen3.6-27B-GPTQ-Pro-4Bit \
  --dtype float16 \
  --quantization gptq_marlin \
  --disable-custom-all-reduce \
  --tensor-parallel-size 2 \
  --max-model-len 132144

Transformers

python

from gptqmodel import BACKEND, GPTQModel

model = GPTQModel.load(
    "groxaxo/Qwen3.6-27B-GPTQ-Pro-4Bit",
    backend=BACKEND.GPTQ_MARLIN,
    device="cuda:0",
)

print(model.generate("Write a short deployment checklist.", max_new_tokens=64)[0])

Notes

Tested with tensor parallel size 2 on RTX 3090 GPUs.
Use float16 and gptq_marlin for the most reliable vLLM startup path.
The quantization and serving workflow lives in the GPTQ-Pro repository above.
MTP/speculative decoding is detected by vLLM for this model, but on 2x RTX 3090 the exact --max-model-len 262144 launch OOMs during KV-cache setup.
The working local vLLM configuration I verified is --max-model-len 65536 with --enforce-eager; that starts and serves, but the current metrics showed spec_decode_num_accepted_tokens_total=0, so it does not improve speed yet.
If you test MTP, use --speculative-config '{"method":"mtp","num_speculative_tokens":2}' and disable thinking in the request payload when you want a plain answer.

⚡ Speed Benchmarks

Tested on 2× NVIDIA RTX 3090 with vLLM (gptq_marlin, tensor-parallel=2, float16).

Metric	Value
Avg Generation Speed	64.0 tok/s
Median Generation Speed	64.0 tok/s
Peak Generation Speed	65.0 tok/s
Avg Time-to-First-Token	54 ms
Median TTFT	56 ms

📋 Detailed Run Results

Test 1: Short Prompt → 256 Tokens (Streaming)

Run	TTFT	Tokens	Speed	Total Time
1	60 ms	256	64.0 tok/s	4.04s
2	55 ms	256	64.0 tok/s	4.04s
3	56 ms	256	62.4 tok/s	4.14s

Test 2: Medium Prompt → 512 Tokens (Non-Streaming)

Run	Tokens	Speed	Total Time
1	512	62.9 tok/s	8.15s
2	512	63.0 tok/s	8.13s
3	512	62.9 tok/s	8.14s

Test 3: Short Burst → 64 Tokens (Streaming)

Run	TTFT	Tokens	Speed
1	50 ms	64	65.0 tok/s
2	56 ms	64	64.9 tok/s
3	56 ms	64	64.7 tok/s
4	54 ms	64	64.9 tok/s
5	48 ms	64	64.9 tok/s

📊 Quality Evaluation

Wikitext-2 test perplexity: 6.366 (n_ctx=1024)

Excad/Qwen3.6-27B-GPTQ-Pro-4bit

🚀 Qwen36-27B-GPTQ-Pro-4Bit