Complete procedures with a way back.

Install and compare Ollama and LM Studio on one workstation using the same model, quantization, prompt, context, hardware, and bounded API harness. Separate GUI convenience, model management, GPU support, privacy, and headless automation from measured latency.

Run one pinned Qwen3-4B Q4_K_M GGUF through llama.cpp, Ollama, and LM Studio on the same machine, normalize the prompt and generation contract, measure cold and warm behavior, blind-score identical outputs, and choose a runner from control, automation, UX, operations, and workload evidence rather than reputation.

Build a repeatable capacity-and-quality matrix for local GGUF models instead of choosing from a model leaderboard or a vendor logo. Inventory the real machine, calculate a safe memory envelope, pin Qwen3 4B, 8B, and 14B candidates, run llama.cpp b9637 with the appropriate CPU, Metal, CUDA, ROCm, or Vulkan backend, and select the smallest candidate that passes the workload at the required concurrency.

Select a licensed, checksum-backed GGUF and measured quantization, build llama.cpp from a pinned commit, size CPU/GPU resources, validate metadata and quality, isolate llama-server behind a trusted proxy, benchmark real workloads, and roll back the complete binary/model bundle.