What Ollama is and what it needs from your system

Ollama is software that lets you run large language models — the AI systems behind chatbots like ChatGPT — directly on your own computer instead of sending your data to a server. You read Ollama, choose which model to run, and the software handles the rest. It works on Windows, Mac, and Linux.

Before you install it, check what you have. Ollama runs on most modern computers, but it works faster and smoother if your machine has a dedicated graphics card (GPU) rather than relying only on your processor (CPU). An Nvidia GPU is ideal; AMD and Apple Silicon chips also work well. If you have only a CPU, Ollama still runs — it will just be slower, especially with larger models.

You will also need disk space. A small model like Mistral takes about 4 GB. Larger ones like Llama 2 can take 13 GB or more. Check your free space before starting. Ollama itself is about 500 MB, but the models are the real storage cost.

Key Takeaways

  • read Ollama from ollama.ai, run the installer for your operating system, and follow the on-screen prompts — the whole process takes a few minutes.
  • After installation, open a terminal or command prompt and type ollama pull mistral to read your first model; this can take several minutes depending on your internet speed.
  • Run a model by typing ollama run mistral in the terminal, then type your question or prompt at the cursor.
  • Your GPU (if you have one) will handle the heavy computation; if you only have a CPU, the model will run slower but still work.
  • Models run locally on your computer, so your prompts and responses stay on your machine — nothing goes to a cloud server.

Downloading and installing Ollama

Go to ollama.ai in your web browser. You will see a large read button. Click it, and the site will detect your operating system and offer the right installer for Windows, Mac, or Linux.

On Windows, the installer is a .exe file. Double-click it, accept the license agreement, and choose where to install (the default location is fine). The installer will add Ollama to your Start menu and create a system service that runs in the background. Click Finish when done.

On Mac, the installer is a .dmg file. Open it, drag the Ollama icon into your Applications folder, and wait for the copy to finish. Then open Applications, find Ollama, and double-click it to launch. You may see a security prompt asking for your password — this is normal and required.

On Linux, open a terminal and paste the command shown on the Ollama website (it starts with curl). This downloads and installs Ollama in one step. After it finishes, close the terminal and reopen it so the system recognizes the new software.

Downloading your first model

After installation, open a terminal (Mac and Linux) or Command Prompt (Windows). On Windows, press the Windows key, type cmd, and press Enter. On Mac, press Command + Space, type terminal, and press Enter. On Linux, open your terminal process from the menu.

In the terminal, type ollama pull mistral and press Enter. Ollama will read the Mistral model, which is small, fast, and good for learning. The read can take 5 to 15 minutes depending on your internet speed. You will see a progress bar showing the read percentage.

If you want a different model instead, you can find others on the Ollama website. Popular choices are llama2 (larger and more capable, but slower), neural-chat (optimized for conversation), or orca-mini (very small and fast). The command is always ollama pull [model-name].

Once the read finishes, the model is stored on your computer and ready to use. You do not need to read it again unless you delete it.

Running a model and asking it questions

In the same terminal window, type ollama run mistral and press Enter. The model will load — this takes a few seconds the first time — and you will see a prompt that looks like >>>. This means the model is ready for input.

Type your question or prompt and press Enter. For example, you could type What is the capital of France? or Write a short poem about rain. The model will think for a moment (longer on a CPU, faster on a GPU) and then type out its response line by line.

After the response finishes, you will see the prompt again. You can ask another question, or type exit and press Enter to quit. The model stays loaded in memory while you are using it, so switching between questions is fast.

Understanding what happens to your data and performance

Everything you type into Ollama stays on your computer. The model runs locally, meaning your prompts, responses, and any files you reference never leave your machine. This is different from ChatGPT or other cloud-based AI, where your input goes to a company's server.

Performance depends on your hardware. On a modern GPU (Nvidia RTX 3060 or better, or Apple M1 and newer), Mistral will respond in a few seconds. On a CPU alone, the same response might take 30 seconds to a minute. Larger models are slower across the board. If your computer feels sluggish while running Ollama, close other programs or switch to a smaller model.

Ollama uses significant RAM while a model is running — typically 4 to 8 GB for smaller models, more for larger ones. If your computer has less than 8 GB of RAM total, you may experience slowdowns. You can check how much RAM you are using by opening Task Manager (Windows), Activity Monitor (Mac), or System Monitor (Linux) while Ollama is running.

Managing models and freeing up space

To see which models you have downloaded, type ollama list in the terminal. This shows the model name, size, and when you last used it.

If you want to remove a model to free up disk space, type ollama rm [model-name]. For example, ollama rm mistral deletes the Mistral model. You can always read it again later with ollama pull.

Models are stored in a folder on your computer. On Windows, this is usually C:\Users\[YourUsername]\.ollama\models. On Mac, it is ~/.ollama/models. On Linux, it is also ~/.ollama/models. You can browse this folder to see how much space each model uses, but it is easier to use the ollama rm command.

Troubleshooting common installation problems

If Ollama does not start after installation, restart your computer. On Windows, check that the Ollama service is running by opening Services (press Windows key, type services.msc, and press Enter). Look for "Ollama" in the list. If it says "Stopped", right-click it and select "Start".

If a model read fails or stops partway through, type ollama pull [model-name] again. Ollama will resume from where it left off rather than starting over.

If Ollama runs very slowly or your computer becomes unresponsive, you may not have enough RAM or your CPU is maxed out. Close other programs, or try a smaller model like orca-mini instead of llama2. You can also limit how much CPU Ollama uses, though this requires editing a configuration file — the Ollama documentation covers this if you need it.

If you see an error about your GPU not being recognized, Ollama will fall back to CPU mode automatically. This is not a failure — it just means the model will run slower. GPU support requires specific drivers; check the Ollama documentation for your graphics card brand if you want to set it up.

Frequently Asked Questions

Can I use Ollama while other programs are running?

Yes, but your computer will be slower. Ollama and other programs compete for RAM and CPU time. Close heavy applications like video editors or games before running a large model. Smaller models like Mistral use less resources and are more forgiving.

What is the difference between the models Ollama offers?

Mistral is fast and small (4 GB), good for quick answers. Llama 2 is larger (13 GB) and more capable but slower. Neural-chat is optimized for conversation. Orca-mini is tiny (3 GB) and very fast but less accurate. Start with Mistral, then try others to see what works for your use case.

Do I need an internet connection to run Ollama after I read a model?

No. Once a model is downloaded, Ollama runs entirely offline. You need internet only to read or update models. This is one of the main advantages over cloud-based AI services.

Will running Ollama damage my computer or wear out my hardware?

No. Running Ollama uses your CPU and GPU normally, the same way any demanding program does. It will not shorten the lifespan of your hardware. Your computer may get warm and use more power, but this is temporary and stops when you close Ollama.

Can I use Ollama with a web interface instead of the terminal?

Yes. Several third-party interfaces exist, like Open WebUI, which gives you a ChatGPT-like interface in your browser. These connect to Ollama running in the background. The Ollama documentation links to community projects if you want to explore this option.