# Microsoft says MAI-Base-2 pre-training is complete; the 2.8-trillion-parameter model moves to post-training

Canonical page: https://technooptimist.io/stories/microsoft-says-mai-base-2-pre-training-is-complete-the-2-8-trillion-1ef73ae4
Date: 15 Oct 2026
About: [Microsoft](https://technooptimist.io/companies/microsoft.md) · [MAI Superintelligence Models](https://technooptimist.io/ai/mai-models.md)
Original source: https://microsoft.ai/news/frontier-pre-training-at-microsoft-ai/

Microsoft says pre-training of MAI-Base-2 is complete and the model is now in post-training, with results promised soon. It is a mixture-of-experts design: only a fraction of its weights run for each token. Microsoft also says preparations for a successor, MAI-Base-3, have started, without a date.

## Key facts

- Size: 80 billion active parameters out of 2.8 trillion total.
- Training ran on 16k GB200 GPUs over 38 days in August and September 2026, with average model FLOPs utilisation of 21% and goodput of 89%.
- No release date for MAI-Base-2 is given; Microsoft plans to license its weights to trusted partners through Foundry, timing not stated.
- MAI-Base-3 preparations are underway; no date given.

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