Apple said on Monday that the artificial intelligence models underpinning Apple Intelligence, its AI system, were pre-trained on processors designed by Google, a sign that big tech companies are looking for alternatives to Nvidia when it comes to the training of cutting-edge AI.

Apple’s choice of Google’s homegrown Tensor Processing Unit (TPU) for training was detailed in a technical paper just published by the company. Separately, Apple released a preview version of Apple Intelligence for some devices on Monday. It's unknown if Apple worked with the latest advanced version of Google's Trillium TPU for training Apple AI.

Nvidia’s pricey graphics processing units (GPUs) dominate the market for high-end AI training chips, and have been in such high demand over the past couple years that they’ve been difficult to procure in the quantities needed. OpenAI, Microsoft, and Anthropic are all using Nvidia’s GPUs for their models, while other tech companies, including Google, Meta, Oracle and Tesla are snapping them up to build out their AI systems and offerings.

Meta CEO Mark Zuckerberg and Alphabet CEO Sundar Pichai both made comments last week suggesting that their companies and others in the industry may be overinvesting in AI infrastructure, but acknowledged that the business risk to doing otherwise was too high.

“The downside of being behind is that you’re out of position for like the most important technology for the next 10 to 15 years,” Zuckerberg said on a podcast with Bloomberg’s Emily Chang.

Apple doesn’t name Google or Nvidia in its 47-page paper, but says that its Apple Foundation Model (AFM) and AFM server are trained on “Cloud TPU clusters.” That means Apple rented servers from a cloud provider to perform the calculations.

“This system allows us to train the AFM models efficiently and scalably, including AFM-on-device, AFM-server, and larger models,” Apple said in the paper.

This is the second technical paper about Apple’s AI system, after a more general version was published in June. Apple said at the time that it was using TPUs as it developed its AI models. For more on this, read the full CNBC report.