Choosing the Right Open-Source LLM Variant & File Format
Why do open-source LLMs have so many confusing names?
You've probably seen model names like Llama-3.1-8B-Instruct.Q4_K_M.gguf or Mistral-7B-v0.3-A3B.awq and wondered what all those suffixes mean. It looks like a secret code, but the short answer is: they tell you two critical things.
Open-source LLMs vary along two independent dimensions:
- Model variant – the suffix in the name (
-Instruct,-Distill,-A3B, etc.) describes how the model was trained and what it's optimized for. - File format – the extension (
.gguf,.gptq,.awq, etc.) describes how the weights are stored and where they run best (CPU, GPU, mobile, etc.).
Think of it like this: the model variant is the recipe, and the file format is the container. You can put the same soup (recipe) into a thermos, a bowl, or a takeout box (container) depending on where you plan to eat it.
Understanding both dimensions helps you avoid downloading 20 GB of the wrong model at midnight and then spending hours debugging CUDA errors.