GPT-5.6 Sol Launches Ultrafast Mode, Speed Increased 14x

OpenAI previews the Ultrafast mode of GPT-5.6 Sol, with output speeds reaching up to 750 tokens per second, a 14-fold increase compared to before, powered by Cerebras. The two parties signed a $10 billion cooperation agreement earlier this year. The service will initially be available only to specific customers via the OpenAI API, with OpenAI planning to gradually expand access as compute capacity grows. OpenAI has already used this mode internally for incident response and plans to use speed as a new pricing lever.