OpenAI posted a preview of Ultrafast mode for its GPT-5.6 Sol model. The announcement states the mode reaches up to 14x the speed of standard inference. It launches first in the OpenAI API to a select group of customers. Several OpenAI staff including Greg Brockman and Boris Power shared the post. One reply noted potential for more synchronous interactive work. Separate posts from Andrew Feldman and Gavin Baker described running GPT-5.6 Sol on the mode through a 2,500-question benchmark in 11 hours and 11 minutes.