Can't inference GPT-OSS-120b-Eagle3 on GB10

We tried to integrate GPT-OSS-120B Eagle3 model which provided by NV on Hugging Face.
Attached pls see our RD’s inputs and error log as attached (Harmony parsing failed in log.txt).

[Test condition]:

  1. Inference runtime: TensorRT-LLM: 1.2.0rc1
  2. LLM models: “openai/gpt-oss-120b” + “nvidia/gpt-oss-120b-Eagle3”

[Error message]:

[TensorRT-LLM][WARNING] Attention workspace size is not enough, increase the size from 33559808 bytes to 33560320 bytes

[11/28/2025-10:40:51] [TRT-LLM] [W] Failed to parse harmony messages from tokens: %s Unexpected EOS while waiting for message header to complete

[11/28/2025-10:40:51] [TRT-LLM] [W] Failed to parse harmony output: %s. Raw output: %s Harmony parsing failed: Unexpected EOS while waiting for message header to complete <|channel|>!!!

[11/28/2025-10:40:51] [TRT-LLM] [W] ⚠️ Harmony parsing fell back to raw text decoding

INFO: 127.0.0.1:38062 - “POST /v1/chat/completions HTTP/1.1” 200 OK

Since NVIDIA’s developer site mentions that the GPT-OSS-12B “Eagle” model supports execution on the Blackwell architecture and delivers up to 3× performance improvement in GB200 testing,
and our GN100 is also based on the Blackwell architecture (GB10), it should theoretically be able to run the GPT-OSS-12B Eagle model and achieve a certain level of performance enhancement.

check.txt (972 Bytes)

script.txt (1.4 KB)

log.txt (27.7 KB)

Please take a look at this and adapt to your scenario:

The image used is nvcr.io/nvidia/tensorrt-llm/release:1.2.0rc4

The GitHub case mentioned above is different from our original question.

We noticed a very similar issue on GitHub (https://github.com/NVIDIA/TensorRT-LLM/issues/8713), but that issue has not been resolved yet.

Anyone tried Eagle3 inference on GB10?

The issue got resolved on those 2 patches:

And they’re available since release Release v1.2.0rc6 · NVIDIA/TensorRT-LLM · GitHub

I intend to play with Eagle3 and gpt-oss-120b with vLLM on the spark at some time in the future.

My previous attempts showed some low acceptance rates which were made even lower after I quantized some layers.

Also, vLLM doesn’t have a tree-base speculative decoding - so it’s unable to take full advantage of Eagle3.

I have a note for myself to play with these: