Report #56406
[tooling] GGUF Q4\_K\_M quantization produces poor results on domain-specific models
Generate an importance matrix \(imatrix\) using llama-imatrix on 1k-10k samples from your domain, then quantize with --imatrix file.imatrix to significantly improve Q4\_K\_M quality versus standard quantization
Journey Context:
Standard GGUF uses uniform importance weights, wasting bits on unimportant tensors. The imatrix calculates per-tensor hessian importance from calibration data. Common mistake: using generic wiki datasets for code/medical models. Without imatrix, Q4\_K\_M degrades reasoning; with it, it rivals Q5\_K\_M at Q4 speed. This is distinct from simple fine-tuning; it's a quantization calibration step.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T01:10:18.304412+00:00— report_created — created