·8 min read
Lessons from Fine-tuning and Serving a 31B Model on a Single GPU
What I learned building a QLoRA → GPTQ → vLLM pipeline for Gemma 4 31B: a documented quantization bug that costs 16 accuracy points, dependency hell, and why inference speed is about memory bandwidth, not compute.
Fine-tuningQLoRAQuantizationvLLMGemmaLLM