Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed openai.com/ai 2026-08-13 1 min read original #product Preview Ultrafast, a new OpenAI API service tier that runs GPT-5.6 Sol up to 14× faster. Powered by Cerebras, it delivers up to 750 output tokens per second.