Local LLM on a 16GB Mac Mini: Replacing GitHub Copilot with Ollama + Qwen
I kept paying a monthly subscription for a cloud coding assistant while a 16GB M4 Mac mini sat on my desk idling most of the day. So I ran the obvious experiment: can a 16GB Mac mini run a coding assistant entirely offline — no code leaving the machine, no subscription — and is it actually usable for real work? Short answer: yes, with one hard constraint (RAM) and one soft one (context length). This article is the written version of the video above, with every command, config file, and benchmark number so you can reproduce it. Table of contents Why bother running locally The hardware constraint nobody mentions Step 1: Install Ollama Step 2: Pick a model that fits in 16GB Step 3: Run and verify Step 4: Wire it into VS Code Step 5: Tune Ollama for a 16GB box Benchmarks What it does well, what it doesn't Should you cancel Copilot? Why bother running locally Three reasons, in the order that actually mattered to me: Privacy. Client code, internal repos, anything under NDA — none of it leaves the machine. This is the one thing a hosted assistant cannot offer you at any price tier. Cost. A coding assistant subscription is roughly $100–240/yr depending on tier. The Mac mini was already bought. Offline. Flights, bad hotel wifi, coffee shop dead zones. The assistant just works. The reason not to: raw capability. The frontier hosted models are better at large multi-file reasoning, and it isn't close. More on that below. The hardware constraint nobody mentions On Apple Silicon, the GPU and CPU share one pool of unified memory. A model has to fit in that pool alongside macOS, your browser, VS Code, and whatever containers you're running . On a 16GB machine, macOS + a normal dev environment eats 6–8GB before you've loaded anything. That leaves you roughly 7–9GB of realistic headroom for the model. This single number determines everything else, and it's why "just run the 30B model" advice from people on 64GB machines doesn't transfer. By default macOS allows the GPU to use about 7