Bloomberg reports that the revamped Siri will be powered by Gemini, and Apple will be paying Google about $1 billion annualy for the AI model with a 1.2 trillion parameter which Google developed. A parameter is a measure of how the model provides responses and understand queries.
The current version of Apple Intelligence based on the cloud has 150 billion parameters. There aren’t particular metrics that show how other models of the company measure up in terms of parameters. Gemini will be used by Apple for functions associated with task planning in multiple steps, execution and summarizing.
An MoE or Mixture-of-Experts architecture is used by Gemini. Apple has considered using their own models of AI for the revamped Siri but decided to opt for Gemini. The revamped Siri rollout has been delayed to next year due to unsatisfying results from the AI, and it will likely be introduced in one of the updates for iOS 26.4.

