Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed
What changed
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.
Why it matters
A concrete addition to Practical AI: Tools, Models & Frameworks: it changes what's available to builders today rather than being general commentary.
How it compares
Related prior coverage to compare against:
- Improving GPT‑5.6 Sol in ChatGPT—and expanding access to GPT-5.6 Luna for free users
- OpenAI partners with Cerebras
- Retiring GPT-4o, GPT-4.1, GPT-4.1 mini, and OpenAI o4-mini in ChatGPT
Sources
- Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed (openai-blog)primary