Qwen 3.6 27B GGUF Quality Benchmark: unsloth, lmstudio-community, Jackrong, bartowski, mradermacher, ubergarm, ggml-org compared

87 GGUF quants from 7 uploaders, measured by KL divergence against the BF16 reference using ~250,000 tokens of coding, chat, tool calling, science, non-Latin scripts, and long documents. Full methodology.

• unsloth/Qwen3.6-27B-GGUF (21 quants)

• lmstudio-community/Qwen3.6-27B-GGUF (3 quants)

• Jackrong/Qwen3.6-27B-GGUF (11 quants)

• bartowski/Qwen_Qwen3.6-27B-GGUF (26 quants)

• mradermacher/Qwen3.6-27B-i1-GGUF (23 quants)

• ubergarm/Qwen3.6-27B-GGUF (2 quants, ik_llama.cpp)

• ggml-org/Qwen3.6-27B-GGUF (1 quant)

The best quant at each size. If it’s not in this table, a smaller file with lower KL exists.

• This is the most competitive uploader field so far. bartowski and mradermacher tie at 12 frontier positions each, unsloth has 10. No single uploader dominates.

• ubergarm’s ik_llama.cpp quants earn both their frontier spots: IQ5_KS (19.9 GB, KL 0.128) and IQ4_KS (15.8 GB, KL 0.209). These special, ik_llama.cpp-only data types show their worth in this dense model.

• Jackrong has 0 frontier appearances out of 11 quants. All are dominated by bartowski or unsloth at similar sizes. lmstudio-community also has 0.

• Q8_0 has KL 0.075, similar to the Qwen 3.6 35B A3B (0.069) and better than the Qwen 3.5 27B (0.120).

• Even at IQ2_XXS (8.4 GB), the model retains 77.5% top-1.

Long documents dominate the quality loss: UD-Q8_K_XL scores KL 0.001 on coding but 0.373 on long documents. Tool calling is the second worst category throughout.

• Inference: TextGen + patched llama.cpp (logprob extraction from prompt)

• Reference: BF16 GGUF by unsloth

• Dataset: ~250,000 tokens across 6 categories (coding, general chat, tool calling, science, non-Latin scripts, long documents)

• Input format: full OpenAI-compatible messages rendered through the model’s Jinja2 chat template

• Metric: KL divergence, computed token-by-token between reference and quantized top-40 log-probability distributions

Full methodology

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