~21 tok/s Gemma 4 on a Ryzen mini PC: llama.cpp, Vulkan, and the messy truth about local chat

Hands-on guide based on a real setup: Ubuntu 24.04 LTS, AMD Radeon 760M (Ryzen iGPU), lots of RAM (e.g. 96 GiB), llama.cpp built with GGML_VULKAN, OpenAI-compatible API via llama-server, Open WebUI in Docker, and OpenCode or VS Code (§11) using the same API. Who this is for: if you buy (or plan to buy) a mini PC or small tower with plenty of RAM and disk, this walkthrough gets you to local inference — GGUF weights on your box, chat and APIs on your LAN, without treating a cloud vendor as mandat...