Ornith-1.0-35B-NVFP4A16

Ornith-1.0-35B-NVFP4A16

NVFP4A16 W4A16 quantisation of deepreinforce-ai/Ornith-1.0-35B — a 35B Mixture-of-Experts (256 routed experts, 8 active, + 1 shared expert) multimodal model with a hybrid linear+full attention stack and a vision tower. Produced with llm-compressor.

Quantisation

• Scheme: NVFP4A16 W4A16 — 4-bit FP4 weights (FP8 E4M3 per-group scales, group_size=16) with bf16 activations.
• Tooling: llm-compressor 0.12.0 + compressed-tensors 0.17.1, transformers 5.8.1, on a Blackwell RTX PRO 6000 (SM120).
• Quantised: the 256 routed mlp.experts.* FFNs, the mlp.shared_expert FFN, and the full-attention self_attn projections.
• Kept in bf16 (quantization_config.ignore): lm_head, all model.visual.* (vision tower), the entire linear_attn Mamba/SSM block (in_proj_*, out_proj, conv1d), the MoE router mlp.gate, and mlp.shared_expert_gate.
• No MTP head: the Ornith base ships 0 mtp.* tensors (despite mtp_num_hidden_layers: 1 in its config), so there is no speculative-decoding head to preserve or graft.
• Recipe: recipe.yaml.

Quality

KLD is per-token KL divergence vs the bf16 base over 8 neuralmagic/calibration samples (max_seq=1024). Because transformers cannot execute the fused-MoE compressed checkpoint (see below), the checkpoint was decompressed to bf16 — applying the quant→dequant round-trip so precision loss is captured — and evaluated there. PPL is wikitext-2-raw (test), non-overlapping 2048-token chunks, identical tokenizer to the base.

NVFP4A16 keeps activations in bf16, so the measured KLD below is exact for this scheme.

Inference — vLLM / SGLang (not transformers)

⚠️ This compressed MoE checkpoint does not run under 🤗 transformers. Qwen3_5MoeForConditionalGeneration fuses the experts into a 3D torch._grouped_mm kernel that rejects fp8/fp4 weights (RuntimeError: Expected mat_a to be Float32, BFloat16 or Float16 matrix, got Float8_e4m3fn), and the per-expert scales load as UNEXPECTED keys. Serve it with vLLM or SGLang, which have the compressed-tensors fused-MoE kernels.

vllm serve lflare/Ornith-1.0-35B-NVFP4A16 \
    --trust-remote-code \
    --gpu-memory-utilization 0.85 \
    --max-model-len 8192 \
    --quantization compressed-tensors

On Blackwell (RTX PRO 6000 / B200, SM120/SM100): FlashInfer's JIT arch probe currently mis-detects SM120 and aborts engine startup (FlashInfer requires GPUs with sm75 or higher). Disable it:

TORCH_CUDA_ARCH_LIST=12.0+PTX VLLM_USE_FLASHINFER_SAMPLER=0 VLLM_USE_FLASHINFER=0 \
    vllm serve lflare/Ornith-1.0-35B-NVFP4A16 --trust-remote-code --quantization compressed-tensors --max-model-len 8192

Validated on an RTX PRO 6000 (SM120) with vLLM 0.24.0: both the FP8 and NVFP4A16 quants load and generate coherently (e.g. "17 times 24 is 408", correct multi-step reasoning traces).