The model loaded. The fans settled. Then the first useful answer took long enough to make the cloud look tempting again.
The verdict up front: before blaming the mini PC, check 3 things: model architecture, quantization, and context length. Start with a Q4_K_M model that leaves memory headroom, test it on your own prompts, and keep its API bound to your machine on shared Wi-Fi.
Leave room around the model
On an Apple silicon Mac or a Strix Halo box such as the GMKtec EVO-X2, the processor and graphics share one memory pool. Model weights, context, the runtime, and your open apps all draw from it.
| Unified or shared memory | Sensible starting point | Main constraint |
|---|---|---|
| 24 to 32GB | 7B to 14B models | A 27B model leaves little working room |
| 48GB | Qwen3.8-27B at Q4_K_M | Long context and a second large model |
| 64GB | 27B model plus a smaller helper | Dense 70B models need tighter compromises |
| 128GB | Large MoE models or dense 70B | Architecture can matter more than fit |
A Q4_K_M build of Qwen3.8-27B occupies roughly 16 to 19GB before context and runtime overhead, according to IntuitionLabs. Do not mistake “loads” for “runs comfortably.”
Use Q4_K_M as a baseline, not a religion
Q4_K_M is a practical first download because it cuts memory use without dropping to the most aggressive compression. If the model only fits below Q4, a smaller model at a healthier quantization is usually the cleaner trade.
Q5 or Q6 may be worth testing when code or careful reasoning matters and memory is available. Keep the prompt and sampling settings fixed while comparing them, or you will learn more about randomness than quantization.
Context has its own bill. A model with a huge advertised window can reserve several extra gigabytes as the conversation grows, so keep one short-context preset for everyday work and one longer preset for document-heavy sessions.
Separate waiting for the first token from generation speed
A long prompt can make the opening pause feel broken even when the answer streams quickly afterward. Apple’s M5 MLX testing found much faster time to first token than a comparable M4, while later token generation remained limited by memory bandwidth.
For the stream itself, about 20 tokens per second feels conversational; 5 to 8 is readable but deliberate. Treat those as comfort bands, not promises. Strix Halo results range from roughly 5 tokens per second for dense 70B models to about 31 for gpt-oss-120b because its mixture-of-experts design activates far fewer parameters per token.
Run a repeatable 500-token answer on the model you will actually use. A benchmark for a different architecture is scenery, not a travel plan.
Keep the API on your side of the door
LM Studio and Ollama can expose OpenAI-compatible local endpoints, which lets an agent use the mini PC much like a private API. On coworking, hotel, or apartment Wi-Fi, bind the service to localhost and leave LM Studio’s Serve on Local Network option off.
That setting is the boundary. The model being local does not protect a server you deliberately expose to everyone on the same network.
Test the trip before taking it
- Generate the same 500-token answer twice and record both first-token delay and generation speed.
- Save the exact model filename, quantization, context setting, and a few prompts you can rerun after updates.
- Restore one real file from the backup drive, such as a Samsung T7 Shield 4TB.
- Turn Wi-Fi off and confirm the runtime, model, and working documents still open.
Who should skip
If you already benchmark models daily, these defaults are behind you. If every task goes to the cloud, the local server is extra luggage.
Still choosing the machine? Start with the packable local LLM workstation guide.
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