What was re-measured for this version (2026-09-07, temperature 0, thinking off, same serving config as bf16)
Table with columns: Axis, bf16 original, This model (W4A16), How to read it| Axis | bf16 original | This model (W4A16) | How to read it |
|---|
| KoBBQ ambiguous-context abstention (8,139) | 92.8% | 93.0% | Same (EXAONE 4.5: 65.7%) |
| Change in disambiguated-context accuracy (vs. base 90.66) | −2.1pp | −2.9pp | Within the pre-registered −3pp allowance, at the boundary |
| Conditional bias (among answered items) | 0.861 | 0.859 | Both miss the pre-registered target of 0.60 (structural — see the bf16 card) |
| Identity probe (8-language holdout, n=240) | 96.2% | 94.6% | 4-item difference out of 240, at the shipping threshold of 95 |
| MMLU English 1,000 (thinking off) | 80.9% | 80.7% | Within detection limit |
| Thinking-mode empty responses (100) | 0 | 0 | No format defect |
| Korean human-likeness pairwise win rate (n=175) | +14.3pp | +9.1pp | Judge uncalibrated, direction only |
| HumanEval (executed, same run, n=154) | 95.0% | 96.1% | +1.1pp, within detection limit |
| KMMLU 1,000 (same run) | 51.0% | 53.8% | +2.8pp |
| Instruction following 100 (deterministic checker) | 78% | 79% | Equivalent |
In one line: abstention behavior is the same as bf16, and over-abstention and identity
have each come down to the edge of their allowance. Capability gates
(coding·KMMLU·instruction) were re-measured in the same run with bf16 as the reference
arm and entered into the table above. The difference from the bf16 card's absolute
values is because the runs differ; read the comparison only within the same run.
Quantization recipe
llm-compressor 0.13.0 GPTQ · calibration 1,024 samples × 2,048 tokens (chat format, 25%
Korean) · dampening 0.01 · actorder static · scheme W4A16 (MLP) + FP8_DYNAMIC (attention)
· ignore: vision/visual, lm_head, embed_tokens, linear_attn.in_proj_a/b. Took 38
minutes (1x B200). Metadata is in quantize_meta.json; the actual group and ignore lists
are in config.json's quantization_config.
Serving
Because attention is FP8, this requires a GPU with an FP8 kernel (SM89+:
H100·H200·L40S·RTX 40/50). A100 (SM80) has not been verified and has no FP8 activation
path, so correct operation is not guaranteed. On Blackwell, the NVFP4 version is faster.
vllm serve ThakiCloud/Qwen3.8-27B-Human-KO-Safety-W4A16 \
--max-model-len 32768 --kv-cache-dtype fp8 --enable-prefix-caching
vLLM ≥ 0.28 auto-detects the scheme from config.json (compressed-tensors).
Limitations
- The safety axis was measured with KoBBQ alone, and the table above is from a single
build of this quantized checkpoint. Given the noise between requantization builds (our
measured GSM8K figure is 3.56pp), a difference within 3pp is not attributed to the
treatment.
- Identity's 94.6% differs from bf16's 96.2%. If self-introduction accuracy matters, use
bf16.
- Other limitations and data provenance are the same as the bf16 card and
DATA_PROVENANCE.md.
License
Apache-2.0 (same as Qwen/Qwen3.8-27B). See LICENSE · NOTICE.