Guided Build · Local AI Infrastructure
Set Up Ollama
Run private, free, open-weight LLMs directly on your GPU with zero per-token cost, calibrated for 100% GPU execution.
- Time: 15 min
- Cost: $0 free & local
- Stack: Ollama · Qwen3 · PowerShell
- Hardware: NVIDIA/AMD GPU
- 1. Check Setup
- 2. Check VRAM
- 3. Calibrate Context
- 4. Test Model
- 5. Connect Agent
First, verify whether Ollama is already installed and see what models you have on disk. Never delete existing base models.
Inspect Existing Ollama Installation
Ollama runs as a background service on Windows and exposes both a command-line tool and an HTTP server on port 11434.
Open PowerShell and run these commands to check your installed version and current models:
ollama --version; ollama list
✓ Observable Checkpoint
Ollama prints its version (e.g. ollama version is 0.5.x or newer) and lists any models already on disk. If not installed, download from https://ollama.com/download/windows.
Troubleshooting: Command not found or service stopped
ollama is not recognized, check if the installer added Ollama to your user PATH. If Ollama is installed but not responding, look in your system tray or run Start-Process "ollama app.exe".
Inspect GPU VRAM and System RAM
Local LLM speed depends critically on fitting the active model entirely inside your GPU's dedicated VRAM. If even 20% spills into CPU RAM, token generation slows to a crawl.
Run nvidia-smi to check available VRAM and systeminfo for system RAM:
nvidia-smi; systeminfo | findstr /C:"Total Physical Memory"
✓ Observable Checkpoint
Note your total VRAM (e.g. 8192 MiB / 8 GB). On an 8 GB card, Windows DWM uses ~1.5 GB, leaving ~6.5 GB free for models and KV cache.
Troubleshooting: No NVIDIA GPU?
Get-CimInstance Win32_VideoController | Select-Object Name, AdapterRAM to view your graphics hardware. Ollama supports ROCm for modern AMD cards.
Calibrate Context Size for 100% GPU Fit
Default models often allocate a huge context window (32k+ tokens) that swells KV cache memory by several gigabytes, spilling onto the CPU. Creating a custom Modelfile with num_ctx 8192 ensures 100% GPU residency.
Create a calibrated 8k context model from qwen3:8b:
"FROM qwen3:8b`nPARAMETER num_ctx 8192" | Set-Content Modelfile; ollama create qwen3:8b-8k -f Modelfile
✓ Observable Checkpoint
Ollama reports using existing layer... creating new layer... writing manifest... success. The new calibrated model is ready!
Troubleshooting: Base model not pulled yet
qwen3:8b is not on your machine yet, run ollama pull qwen3:8b first. It downloads the ~5.2 GB base weights. Never delete existing models!
Test Inference and Verify 100% GPU Fit
Send a prompt to your calibrated model and inspect its real-time GPU/CPU distribution with ollama ps.
Run a test prompt and verify processor status:
ollama run qwen3:8b-8k "Explain GPU KV cache in two sentences."; ollama ps
✓ Observable Checkpoint
Check the PROCESSOR column in ollama ps. It must say 100% GPU. Total size should be ~6.2 GB with zero CPU offloading.
Troubleshooting: If processor shows CPU offload (e.g. 22%/78%)
num_ctx to 4096 in your Modelfile to fit in tighter VRAM budgets.
Connect Ollama to AI Coding Agents
Ollama provides an OpenAI-compatible endpoint at http://127.0.0.1:11434/v1. You can plug it directly into Cursor, Claude Code, Python scripts, or custom bots.
Test the OpenAI-compatible REST API using PowerShell:
Invoke-RestMethod -Uri "http://127.0.0.1:11434/v1/chat/completions" -Method Post -Headers @{"Content-Type"="application/json"} -Body '{"model":"qwen3:8b-8k","messages":[{"role":"user","content":"Say ready!"}]}' | Select-Object -ExpandProperty choices
✓ Observable Finish Line
You receive a structured response with role: assistant and content: ready!. Your local LLM pipeline is verified and ready for autonomous agent tasks!
PS C:\Users\learner> ollama --version ollama version is 0.5.12 PS C:\Users\learner> ollama list NAME ID SIZE MODIFIED qwen3:8b-8k 2c8b2db94ab4 6.2 GB Just now qwen3:8b def456789abc 5.2 GB 1 day ago qwen2.5:14b 7cdf5a0187d5 9.0 GB 5 weeks ago qwen2.5:7b 845dbda0ea48 4.7 GB 5 weeks ago Ready for Step 1.