Artificial Intelligence

What is Mixture of Experts?

Quick answer

A model design that splits a neural network into specialized sub-networks and activates only a few of them for each input.

Mixture of Experts, explained

In a standard model, every parameter takes part in processing every token. A mixture of experts model instead contains many expert sub-networks plus a router that decides which experts handle each piece of input. Only a small fraction of the model's total parameters is active at any moment.

This design lets developers build models with very large total capacity while keeping the computing cost per request closer to that of a much smaller model. Several well-known large language models use this approach. For a business using such a model through an API, the effect is mostly invisible, appearing as faster or cheaper responses. The trade-offs include higher memory requirements, since all experts must be loaded, and more complex training.

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