[Bug]: Qwen2.5-32B-GPTQ-Int4 inference `!!!!!`

[jklj077]

Your current environment

The output of `python collect_env.py`

N/A; happened to multiple users.

Model Input Dumps

No response

🐛 Describe the bug

We have been receiving reports that the 4-bit GPTQ version of Qwen2.5-32B-Instruct cannot be used with vllm. The generation only contains !!!!!. However, it was also reported that the same model worked using transformers and auto_gptq.

Here are some related issues:

• [Badcase]: Model inference Qwen2.5-32B-Instruct-GPTQ-Int4 appears as garbled text !!!!!!!!!!!!!!!!!! QwenLM/Qwen3#945 (v0.6.1.post2, v0.6.2, v0.6.3)
• [Bug]: Qwen2.5-32b-int4用vllm跑 好像只会生成感叹号 QwenLM/Qwen3#1103 (v0.6.1)
• [Bug]: 使用 Xinference vLLM 启动 qwen2.5-32b-instruct 推理结果都是感叹号 QwenLM/Qwen3#1038 (v0.4.2, v0.5.1)

We attempted to reproduce the issue, which appears related to quantization kernels, and the following is a summary:

• gptq_marlin works
• gptq fails for requests with len(prompt_token_ids)<=50 but works for longer input sequences

The results are consistent for

• tensor-parallel-size: 2, 4, 8
• vllm versions: v0.6.1.post2, v0.6.2, v0.6.3.post1, v0.6.4.post1
• nvidia driver versions: 535.183.06, 560.35.05

As gptq_marlin is not available for turing and volta cards, we are not able to find a workaround for those users. It would help a lot if one could help investigate the issue.

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[youkaichao]

cc @robertgshaw2-neuralmagic

[youqugit]

I encountered the same issue, only the /chat/completions endpoint returns an error that many !!!!!, while the /completions endpoint works fine.

vLLM version: 0.6.1

[DarkLight1337]

Also cc @mgoin

[mgoin]

As far as I can tell the gptq kernel hasn't been touched all year, the last change was #2330 by @chu-tianxiang

This may be a fundamental issue with the kernel for this model, someone would need to dive in and learn about it.

[fsh2102]

I had the same problem when using the Qwen2-72B-Instruct model, is there a solution now

[jklj077]

Hi, it appears that #11493 is about the marlin gptq kernel, while this issue is about the previous gptq kernel. I wonder if it's also fixed.

[wchen61]

Hi, it appears that #11493 is about the marlin gptq kernel, while this issue is about the previous gptq kernel. I wonder if it's also fixed.

Yes, that's right. I didn't notice that this was inferred using the original gptq kernel. My PR addresses the issue within gptq_marlin. We might need to reopen this issue.

[robertgshaw2-redhat]

We do not really have the bandwidth to investigate this so would welcome a contribution from anyone in the community! Additionally, one could explore extending W4 triton kernels to support GPTQ models (currently they run with AWQ only). This could be a good long term solution if anyone is up for a challenge!