North Star AI Consultation

ai on your own computer

Open models, closed models, and what your computer can run.

AI models come in two flavors. Closed models live on a company's servers and you visit them: ChatGPT, Claude, Gemini. Open models are files anyone can download and run at home: no account, no internet, no monthly fee.

Below: how the two differ, what your computer can run today, and what to buy if you want more. Open any row that interests you; skip the rest.

Two kinds of AI models

Every AI tool is built on a model: one specific AI brain with a name and a version. The split that matters is who holds the brain.

closed models

You visit them

The company keeps the model on its servers. You reach it through an app or website; your words travel there and back. You never touch the model itself.

  • The strongest models in the world are closed.
  • You pay a subscription (or use a limited free tier), and the company can change or retire a model at any time.
  • Your conversations pass through the company's servers, under its privacy policy.

ChatGPT, Claude, Gemini

open models

You can take them home

The company releases the model as a downloadable file. Anyone can run it or build on it, mostly free. Run one on your own computer and your words never leave the room.

  • The best open models trail the best closed ones by months, not years.
  • Free to use; the real cost is a computer with enough memory.
  • Once it's on your machine, nobody can take it away, change it, or read your chats.

Qwen (Alibaba), Gemma (Google), Llama (Meta), gpt-oss (OpenAI), DeepSeek, Mistral

Why would a company give away an AI model for free?

Strategy, not charity. Meta, Google, and the rest release open models so the world builds on their technology instead of a rival's, and every improvement the community makes flows back around.

There's also talent and trust: researchers prefer companies that publish, and businesses trust tools they can inspect and keep. None of this makes the models less real or less useful to you. It just explains why billion-dollar software sits on a free shelf.

Is 'open model' the same as 'open source'?

Almost. Truly open source would mean publishing everything: training data, code, the recipe. Most open models publish the finished brain (the 'weights') plus a license letting you use it, and keep the recipe private. Purists say 'open weights'.

For running AI at home, the difference changes nothing: you download the file, it works, it's free. A business building ON a model should skim the license once; using one at home, you'll never notice.

So which is better, open or closed?

Neither. Closed models are smarter; open models are yours. The top closed models win on the hardest work, and the freshest features land there first. (A few giant open models get close, but they need server hardware.)

Open wins on privacy (nothing leaves your machine), cost (free forever once you own the computer), and control (nobody can retire your favorite model). Many people use both: cloud for hard problems, local for private notes and drafts.

What 'running it locally' actually means

The AI brain lives and thinks on YOUR computer. Download a model file once, open a free app (LM Studio is the friendly one; Ollama is the plumbing other tools build on), and chat. You could unplug the internet mid-conversation; nothing is being sent anywhere.

Privacy, for real

Client notes, health questions, financials: nothing goes to any server, full stop. The number one reason people go local.

Free after the hardware

No subscription, no caps, no rate limits. Ask ten thousand questions this month; the bill is your electricity.

Works offline

Planes, dead zones, outages: a local model doesn't notice.

Nobody moves your cheese

Cloud models change and retire on the company's schedule. A local model is a file on your disk; it behaves the same in ten years.

The trade: a model that fits in a laptop is a fraction of the size of the ones behind ChatGPT or Claude, and it shows on hard problems. Bright assistant, not oracle.

What actually happens to my words in cloud AI?

Your conversation is sent to the company's servers, processed, and stored under its privacy policy. The big providers let you opt out of training, and business plans usually promise no training at all. Real protections, but they're policies: promises, not physics.

A local model is physics. There's no server, so there's nothing to trust. For everyday questions the difference rarely matters. For a therapist's notes, a lawyer's drafts, or unreleased numbers, it can matter a lot.

How hard is the setup, honestly?

Easier than setting up a printer. Download LM Studio (free, Mac and Windows), open it, click download on a model it recommends for your machine (it checks your memory and warns you off models that won't fit), and chat. Most of the time is the download.

No command line, no code, no account. And if you'd rather see it before you try it, that's an easy thing to do together in a session.

LM Studio or Ollama: which one is for me?

LM Studio if you want an app with buttons: a chat window, a model store, and clear warnings when a model is too big for your machine. The right first stop for almost everyone.

Ollama if you want other apps to use your local model as a building block; it's the plumbing many local AI tools connect to, with a simple app of its own these days. You can run both; the model files work the same.

The one number that matters: memory

One question decides everything: does the whole model fit in your computer's memory? Model sizes are counted in billions of 'parameters' (an 8B model has 8 billion), and a model needs a bit more than half its number in gigabytes: an 8B model wants roughly 5 GB, a 27B roughly 17 GB, plus breathing room. Not the processor, not the brand. Memory.

Open the size chart: what each model size needs and does
Model size classes, the memory they need, and what they're good for
Model sizeNeeds roughlyWhat you get
1 to 4B2 to 4 GBQuick helpers: fix wording, summarize, brainstorm. Fine on almost any recent computer, including phones.
7 to 9B5 to 7 GBThe everyday class. Real writing and coding help. The most popular local size in the world.
12 to 14B8 to 11 GBA clear step up in judgment and nuance. The comfortable middle for 16 to 24 GB machines.
20 to 32B13 to 20 GBWhere local stops feeling like a compromise. Includes gpt-oss-20b and the 27B Qwen and Gemma models.
70B and up40 GB or moreThe heavyweights. Genuinely close to cloud quality; needs a big-memory Mac or serious PC hardware.

Standard compressed ('quantized') versions, rounded to stay honest. Longer conversations need extra working space, so 'roughly' is doing real work here.

What's a parameter, and why billions of them?

Parameters are the tiny numeric dials inside the model, tuned during training; together they store everything it knows. More dials generally means more capable.

Nobody needs to picture 8 billion of anything. Read 'B' as a size tag: 4B small, 8B everyday, 30B serious, 70B heavyweight. The tag maps straight to memory needed, which is why this whole page runs on it.

What does 'quantized' or 'Q4' mean on a download?

Compression for AI brains: storing the dials with less precision, the way a paperback shrinks a hardcover without losing the plot. The standard 'Q4' versions keep nearly all the smarts at about a quarter the size.

It's the form virtually everyone runs at home, and what this page's numbers assume. Apps like LM Studio pick a sensible version automatically; if you're ever offered a choice, take the one marked 'recommended'.

Why memory and not the processor or 'AI chips'?

To produce each word, the computer sweeps through essentially the entire brain, billions of numbers, again and again. If the whole brain sits in fast memory, the sweep is quick. If it doesn't fit, speed falls off a cliff.

The processor sets how fast the sweep goes; memory decides whether it's possible at all. That's why this page asks about gigabytes, not gigahertz. (The 'NPU' chips in ads mostly accelerate small background features; see the questions below.)

Why are Macs weirdly good at this?

On a typical PC, big models must fit inside the graphics card's own small memory pool: 8, 12, maybe 24 GB on expensive cards. Apple-chip Macs share one big pool of fast 'unified memory', and the model can use about two-thirds to three-quarters of it.

So a 64 GB Mac can hand roughly 45 GB to a model, something a PC needs exotic hardware to match. That's why Macs became the darling of the local AI crowd. (The PC world is catching up: a few 2026 machines borrow the same shared-memory idea, some with up to 128 GB.)

How fast is 'fast enough'?

AI speed is measured in tokens per second; a token is roughly three quarters of a word. People read at about 4 to 5 words per second, so past roughly 6 tokens per second a model feels fluid: it's outrunning your eyes.

An everyday 8B model on a recent Mac or a decent graphics card clears that bar several times over. The slow experiences are mismatches: a model too big for the machine, or a processor doing a graphics card's job. The checker below keeps you out of those.

What can YOUR computer run?

Two taps: what kind of computer, how much memory. You get an honest verdict, models to try, and what to expect.

First: which of these is your computer?

If you're buying a computer for AI

Ignore 'AI PC' stickers. You're buying one thing: fast memory, as much as the budget allows. Prices are mid-2026 ballparks (a worldwide memory shortage pushed them up this year); re-check the week you buy.

First, spend nothing$0

Run the checker above on the computer you already own. If it lands in any tier that runs models, try local AI free for a week before buying anything.

Most people discover the machine they have is enough to know whether they even like this.

The cheapest real ticketroughly $800

A Mac mini with 16 GB of memory: the least expensive machine we'd honestly call good at local AI. The everyday 8B class plus OpenAI's gpt-oss-20b, quietly, on a desk.

Apple's unified memory does the work of a graphics card here. One warning: the cheapest Mac in the lineup (the $699 MacBook Neo) has 8 GB and is NOT this machine.

The sweet spot$1,300 to $2,000

A Mac (mini, Air, or Pro) with 24 to 32 GB of memory, or a desktop PC with a 16 GB NVIDIA card. This opens the 20 to 32B class, where local AI gets genuinely impressive.

The 32 GB Mac route is simplest and quietest; the PC route also buys you gaming and upgrade paths.

The heavyweight ticket$2,500 and up

A Mac with 64 GB or more (Mac Studio or MacBook Pro), a PC with a 24 GB card, or one of the new 128 GB shared-memory PCs. This is 70B territory, and at the top end, gpt-oss-120b territory.

Only worth it when privacy-critical serious work is the plan. Past this point you're building a small home lab, and we'd love to hear about it.

The most honest sentence on this page: a $20-a-month subscription to a top cloud model is smarter than anything a $2,000 computer can run. Buy hardware for privacy, control, offline work, or the joy of it. Not to beat the cloud on brains.

Common questions

Can my phone run a local model?

Yes, genuinely. Recent iPhones and Android flagships run the 1 to 4B class through free apps: useful for summaries, quick drafts, and offline questions.

Temper expectations: phone models are the pocket-knife version, and long sessions warm the phone. A neat, private convenience, not a ChatGPT replacement.

Do I need internet for local AI?

Only once, for the download. Model files are big (a few GB small, tens of GB large), so decent Wi-Fi helps that first fetch.

After that, everything runs with the network unplugged. No connection, no account, no pinging home. That's the point.

Is downloading these models legal? What's the catch?

Fully legal. The companies publish them on purpose, with licenses that allow personal and business use; a few add conditions that only kick in at giant-company scale.

The honest catches are practical: models are only as current as their training date, they make mistakes with confidence, and the downloads are big. If a business use rides on one model, skim its license once; it's a page, not a book.

Will a local model know today's news?

No. Every model only knows what it learned in training. Cloud tools get around this by quietly searching the web before answering; a plain local model can't.

Some local apps bolt on web search, but it's tinkery. If your daily use is 'what's happening right now', cloud fits better. Local shines for writing, thinking, and your own documents.

Can I make images locally too?

Yes. Image generation has its own open models (Stable Diffusion and Flux are the famous names) and free apps, and the same rule applies: more memory, better models.

It's a deeper rabbit hole than local chat: more knobs, more jargon. If your machine scored well in the checker, it can likely make images too.

What's an NPU? Ads say I need an 'AI PC'.

An NPU is a small chip for light AI features: background blur, live captions, photo search. Nice to have, nearly irrelevant to the chat models this page is about, which lean on the graphics side and, always, on memory.

Treat 'AI PC' stickers as marketing. The questions that matter stay the checker's: how much memory, and how fast?

Does local AI make sense for a small business?

Sometimes, when privacy is the driver: client files, medical or legal notes, anything that shouldn't leave the building. One capable Mac can be a private AI workstation for a small team, monthly cost zero.

The trade is capability and convenience: cloud tools are smarter, current, and need no babysitting. Many businesses use both: cloud for general work, local for the sensitive pile. Sorting which is which is exactly what a setup session is for.

Not sure what your machine can do, or what's worth buying? Bring it to your free session. We'll check together, set up a local model if it fits, and tell you straight if the cloud tools are the better deal.

ready when you are

The first hour is free. Bring a real problem.

Two minutes of quick questions, then we reach out to set the time. No pitch, no jargon: the hour happens on your real stuff, and you keep whatever we set up.

Why is the first hour free?

We'd rather prove it than pitch it. And it won't be free forever: as client work fills the calendar, the free hour goes away (a session you've already booked stays free). After that it's $50 an hour online, or $100 for a 90-minute in-person visit, low for the Bay Area on purpose: the AI does the heavy lifting. You'll know the price of anything before we touch it.

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