FR
  • B1
  • Right model, right effort
  • Choose
  • 4 min

Small and large models

Situation

The situation

A small, fast model for simple tasks, a large one for hard ones.

You are the office manager of a 20-person IT services company in Lille. You use AI for many different tasks and want to know when a small model is enough.

Idea 1 of 3

Models come in different sizes

AI models are not all the same size. The number followed by “b” in their name counts their internal settings, in billions: gpt-oss-20b is a small model, gpt-oss-120b a large one. In general, the larger the model, the stronger it is, and the slower.

Idea 2 of 3

Models that reason

Some models, small or large, reason: they think in steps before answering. It helps with an analysis or a calculation. On aidock, each model’s page shows whether it “thinks before answering”: both gpt-oss-20b and gpt-oss-120b do.

Idea 3 of 3

The simple rule

Short, clear, low-stakes task: small model. Analysis, calculation, comparison or decision: large model, ideally one that reasons. If in doubt, start small and move up if the answer falls short.

Question 1 of 2

What is the advantage of a small model?

What is the advantage of a small model?
See the answer

It answers fast and is enough for simple tasks A small model is fast. It can make mistakes like a large one, especially on hard tasks.

Question 2 of 2

You are unsure which model size to use. What do you do?

You are unsure which model size to use. What do you do?
See the answer

You start small, then move up if the answer falls short Starting small saves time on simple tasks. You only move up when you need to.

Exercise

Your turn

Sort each task: small, fast model or large model?

Fix the typos in a three-line email

Small, fast model A short, simple task: a small model does it quickly and well.

Compare three supplier quotes and recommend the best value

Large model You need to cross-check figures and weigh criteria: a job for a large model, ideally one that reasons.

Translate a two-sentence welcome message into German

Small, fast model Short and straightforward: speed matters more than depth.

Work out why quarterly revenue is falling, from a spreadsheet

Large model A multi-step analysis with calculations: a large model is more reliable.

Suggest five subject lines for the newsletter

Small, fast model Short ideas that are easy to judge: a small model is enough.

Spot the risky clauses in a 20-page maintenance contract

Large model A long text with high stakes: you need a strong model, then a human review.

End of the lesson

Lesson complete

Key point

Simple task: small, fast model. Hard task: large model.