Fine-Tune Qwen3.8-27B

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Qwen/Qwen3.8-27B is a dense 27B native vision-language model for text, image, and video inputs. Its language backbone has 64 layers and alternates Gated DeltaNet linear-attention blocks with gated full-attention blocks. The checkpoint uses a 5,120-dimensional hidden state, a 17,408-dimensional feed-forward layer, and a native context length of 262,144 tokens.

NeMo AutoModel loads Qwen3.8-27B through the existing native Qwen3_5ForConditionalGeneration implementation because the Qwen3.6-27B and Qwen3.8-27B checkpoint configs have the same model architecture and dimensions.

Install Dependencies

From a current NeMo AutoModel checkout, install the VLM and Qwen media dependencies:

$uv sync --locked --all-groups --extra vlm-media

Data

Both recipes fine-tune on mmoukouba/MedPix-VQA, a medical visual-question-answering dataset with train and validation splits. The vision tower is frozen, while the language model remains trainable.

For details on adapting another multimodal dataset, see the Multi-Modal Dataset Guide.

Run Full SFT

The full SFT recipe uses BF16, FSDP2 data parallelism, activation checkpointing, and a global batch size of eight:

$uv run automodel --nproc-per-node=8 \
> examples/vlm_finetune/qwen3_8/qwen3_8_27b.yaml

Run LoRA

The LoRA recipe trains rank-8 adapters and excludes the vision tower, image encoder, audio modules, and language-model head from adapter injection:

$uv run automodel --nproc-per-node=8 \
> examples/vlm_finetune/qwen3_8/qwen3_8_27b_lora.yaml

Training Results

The following loss curves come from 100-step runs on one node with eight NVIDIA H100 80GB GPUs. Both runs used the checked-in MedPix-VQA recipes with Weights & Biases logging enabled; validation was disabled for these curve-only runs. The plots show every recorded training-loss value and a trailing 10-step moving average. Full SFT moved from 2.0644 to 1.7925 (minimum 0.9088), while PEFT moved from 2.0639 to 1.8109 (minimum 0.9327).

Full SFT (Weights & Biases run)

Qwen3.8-27B full SFT training loss

PEFT (LoRA) (Weights & Biases run)

Qwen3.8-27B LoRA training loss