Highlights
- Matches or leads
unsloth/Qwen3.8-27B-NVFP4 across CMMLU, C-Eval, and non-thinking MMLU-Pro, with MMLU-Pro essentially at parity.
- Records 0.0265 KL divergence from BF16 versus 0.0391 for the competing build—about 32% lower and measurably closer to the original BF16 output distribution.
- Reaches 61.2 tokens/s single-stream versus 58.5 for the competing build and 27.4 for BF16 on the tested configuration—about 2.2× BF16.
- Delivers near-parity aggregate throughput at 32 concurrent requests: 1284 tokens/s versus 1292; higher concurrency tends to favor the competing build's FP4 kernel path.
- Downloads at 23.29 GB versus 23.4 GB for the competing build.
- NVFP4 4-bit weights for vLLM serving on NVIDIA Blackwell GPUs.

Results
Table with columns: Metric, BF16 baseline, kyaky/Qwen3.8-27B-NVFP4, unsloth/Qwen3.8-27B-NVFP4, Result| Metric | BF16 baseline | kyaky/Qwen3.8-27B-NVFP4 | unsloth/Qwen3.8-27B-NVFP4 | Result |
|---|
| CMMLU accuracy ↑ | 72.03 | 73.55 | 70.76 | +2.80 pp vs competitor |
| C-Eval accuracy ↑ | 74.07 | 75.93 | 73.63 | +2.30 pp vs competitor |
| MMLU-Pro accuracy ↑, non-thinking | 75.43 | 77.14 | 76.57 | Essentially at parity with competitor |
| KL divergence vs BF16 ↓ | 0 (reference) | 0.0265 | 0.0391 | About 32% lower than competitor |
| Download size ↓ |
All comparisons use the same evaluation conditions. Small differences from the BF16 reference should be treated as evaluation variation, not as evidence that this build surpasses the base model's capabilities.
Measured on 1 × NVIDIA RTX PRO 6000 (Blackwell) using vLLM 0.25.1 with greedy decoding and an FP8 KV cache at 8K context. Workload: 256-token generations; single-stream is the mean of 3 runs, concurrent is 32 simultaneous requests. Values are tokens/second and apply only to this tested configuration; they should not be assumed to generalize to other hardware or serving setups.
Table with columns: Metric, BF16 original, kyaky/Qwen3.8-27B-NVFP4, unsloth/Qwen3.8-27B-NVFP4, Result| Metric | BF16 original | kyaky/Qwen3.8-27B-NVFP4 | unsloth/Qwen3.8-27B-NVFP4 | Result |
|---|
| Single-stream generation speed (tokens/s) ↑ | 27.4 | 61.2 | 58.5 | +4.6% vs competitor; about 2.2× BF16 |
| Aggregate throughput at 32 concurrent requests (tokens/s) ↑ | 648 | 1284 | 1292 | Near-parity at this concurrency; both roughly 2× BF16; higher concurrency tends to favor the competing build's FP4 kernel path |
Serve with vLLM
vllm serve kyaky/Qwen3.8-27B-NVFP4 --trust-remote-code
NVFP4 requires an NVIDIA Blackwell GPU, such as an RTX 50-series or RTX PRO 6000-class GPU, and is served through vLLM.
Intended use
Choose this release for a well-rounded 23.29 GB NVFP4 build with competitive benchmark retention, closer measured BF16 fidelity, and strong serving performance on the tested Blackwell configuration. It leads the competing build on CMMLU and C-Eval, remains essentially at parity on non-thinking MMLU-Pro, is faster in single-stream generation, and provides near-parity aggregate throughput at 32 concurrent requests.
kyaky/Qwen3.8-27B-NVFP4 is an independent NVFP4 release derived from Qwen/Qwen3.8-27B. Review the base model card for capabilities, acceptable use, and license terms.