Qwen3.8-27B — FP8 block + AWQ

FP8 block-scaled [128, 128] quantization of Qwen/Qwen3.8-27B with dynamic activations — the same format and the same 882 excluded modules as Qwen's own FP8 release — with one addition they do not use: an AWQ smoothing pre-pass on the BF16 weights.

That single change cuts real damage by 45%: 1.45% → 0.79% confident disagreement, z = +9.80.

Drop-in for vLLM. ~30 GB, 8,656 tok/s (TP=2, B300).

Measured quality

Every row measured identically: 231 documents, 142,727 scored token positions, against the BF16 base.

build size top-1 ↑ near-tie ↓ moderate ↓ confident ↓ certain ↓ divmed ↑ tok/s
➤ this model — FP8 block + AWQ 30 GB 96.22% 22.83% 3.76% 0.79% 0.08% 51 8656
TelperionAI INT4-AWQ-GPTQ 25.1 GB 96.30% 22.29% 3.52% 0.93% 0.09% 48 4617
TelperionAI EXL3 6.5 bpw + AWQ 23.0 GB 97.10% 17.03% 2.41% 1.23% 0.15% 59
TelperionAI EXL3 5.5 bpw + AWQ 20.0 GB 96.12% 22.81% 3.52% 1.34% 0.16% 55
Qwen FP8 (same format, no AWQ) 30 GB 96.15% 22.70% 3.48% 1.45% 0.08% 47 8711
TelperionAI NVFP4 24.7 GB 93.62% 32.25% 8.59% 1.85% 0.16% 29 10521
RadixArk NVFP4 24.7 GB 90.23% 43.80% 14.49% 3.29% 0.70% 11 11436
unsloth NVFP4 24.7 GB 91.75% 40.12% 10.32% 3.91% 0.25% 19 11069
Inferact NVFP4 20.1 GB 84.11% 52.01% 25.70% 10.39% 2.27% 7 11457

EXL3 rows have no comparable tok/s — they run on exllamav3, not vLLM.

How to read this

Columns are disagreement rates against the BF16 base, split by how confident the base model was at that position (its top1−top2 logprob margin):

bucket margin meaning
near-tie < 0.5 numerical noise — harmless
moderate 0.5–2 mild
confident 2–5 real damage
certain > 5 real damage

Only confident and certain matter. divmed is the median token index at which free greedy generation first diverges from the base.

Significance

Paired McNemar over matched token positions, n = 33,812:

vs their confident z verdict
TelperionAI NVFP4 1.85% +14.80 this model better
Qwen FP8 (same format) 1.45% +9.80 this model better
TelperionAI EXL3 5.5bpw+AWQ 1.34% +9.14 this model better
TelperionAI EXL3 6.5bpw+AWQ 1.23% +7.43 this model better
TelperionAI INT4-AWQ-GPTQ 0.93% +2.46 this model better

It also ties the best certain figure in the field (0.08%).

Recipe

  1. AWQ smoothing on the BF16 weights — a pure, function-preserving transform (fold 1/s into the preceding norm, s into the next linear's input dim), calibrated on 256 sequences. Verified function-preserving: the ratio to the original weights is a separable per-row × per-column scale.
  2. FP8 block [128,128] weights with dynamic per-group activations, excluding the same 882 modules Qwen excludes. This stage needs no calibration — weight scales come from the weight tensor alone and activations are scaled at runtime.

Note that the 882 exclusions are not conservatism: FP8 block requires every quantized dimension to be divisible by 128, and the router / shared_expert_gate layers are not.

Why AWQ helps at 8 bits

AWQ corrects activation outliers, which are a property of the model rather than of the quantizer — so it transfers across formats. Measured on this model: NVFP4 3.97% → 2.69%, a 4-bit trellis 3.08% → 2.40%, and block FP8 1.45% → 0.79%. A [128,128] block still spans a wide dynamic range, so outlier channels cost real precision even at 8 bits.

GPTQ and AutoRound do not transfer this way: they are quantizers whose error compensation is tied to specific rounding decisions on a specific grid.

Downloads last month
10
Safetensors
Model size
28B params
Tensor type
BF16
·
F8_E4M3
·
Inference Providers NEW
This model isn't deployed by any Inference Provider. 🙋 Ask for provider support

Model tree for TelperionAI/Qwen3.8-27B-FP8-block-AWQ

Base model

Qwen/Qwen3.8-27B
Quantized
(944)
this model