The arrangement echoes the $1 billion cash-for-computing investment that Microsoft made in OpenAI three years ago. In January, Microsoft announced a further "multiyear, multibillion-dollar" investment in OpenAI estimated at $10 billion. The deal cemented Microsoft's position as exclusive infrastructure provider to one of the world's leading AI startups. Chief executive Satya Nadella claimed that Microsoft had built a supercomputer to handle the OpenAI work, and that it could now handle some AI calculations at half the cost of its rivals. Reducing cost is key for the compute-intensive development of large language models: Estimates put the cost of running ChatGPT, assuming 10 million monthly users, at $1 million per day.