YAML Metadata Warning:empty or missing yaml metadata in repo card

Check out the documentation for more information.

Qwen3.8-27B UD-IQ2_XXS + Q8_0 LM Head (graft)

Custom GGUF for Qwen3.8-27B built by grafting the Q8_0 output/lm_head from the Q8_0-tier Unsloth Dynamic quant onto the IQ2_XXS (Unsloth Dynamic) body.

  • Base: unsloth/Qwen3.8-27B-GGUF -> Qwen3.8-27B-UD-IQ2_XXS.gguf
  • Body: IQ2_XXS (unchanged, byte-identical to base)
  • LM head (output.weight): Q8_0 (1,288 MiB), up from the base Q3_K (521 MiB)
  • output_norm: F32 (unchanged)
  • quantization_version: 4
  • Size: 7.52 GiB (base 6.77 GiB, +767 MiB)

Why: the lm_head is only ~5-9% of the file but is the single highest-leverage tensor for output quality. Holding it at Q8_0 on a 2-bit body yields better next-token logits for a small size cost.

How: header-offset GGUF surgery โ€” output.weight (tensor #1, offset 0) replaced with a Q8_0 blob; all 850 following tensor offsets shifted +767 MiB. Body bytes are byte-identical to the base.

GGUF alignment note (the bug that mattered): GGUF tensor data does not begin at header_end โ€” it begins at the 32-byte-aligned boundary align_up(header_end, 32) (llama.cpp reads it at GGUF_PAD(header_end, 32)). The Q8_0 head was sourced from Q6_K[align_up(Q6_header_end,32)] and the body from base[align_up(base_header_end,32) + old_head], with 3 bytes of alignment padding written after the header in the output.

Validated: loads clean in llama.cpp and produces coherent output:

  • "What is the capital of France?" -> "The capital of France is Paris."
  • "What is 2+2?" -> "4"
  • Fluent paragraph generation on a 2-bit body with the Q8_0 head (~43 t/s on a single RTX 3090).
  • Dequant of the grafted output.weight row-0 matches the official BF16 lm_head (corr ~1.0, max abs err ~3.6e-4).

Earlier revisions of this repo (before the alignment fix) produced garbage ("/////////") because the head was copied from the un-aligned header_end. The current file is the corrected build.

Downloads last month
604
GGUF
Model size
27B params
Architecture
qwen35
Hardware compatibility
Log In to add your hardware

2-bit

Inference Providers NEW
This model isn't deployed by any Inference Provider. ๐Ÿ™‹ Ask for provider support