Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed

Today, we’re sharing an early look at Ultrafast, a new service tier that runs GPT‑5.6 Sol up to 14× faster than Standard processing, launching first in the OpenAI API. Powered by Cerebras, Ultrafast generates up to 750 output tokens per second, bringing our most intelligent model to products and workflows where every second matters.

With GPT‑5.6, we’re pushing the frontier on what our models can do and making them more efficient across every layer of our stack. Those improvements have made advanced intelligence more affordable and more useful to more people. Until now, getting real-time speed typically meant choosing a smaller or more specialized model. Ultrafast points to progress in a new direction: more useful work per second.

When speed no longer requires giving up intelligence, AI can move into the most time-sensitive parts of a business and new kinds of work become possible. We’ve already seen some encouraging scenarios for Ultrafast:

• Incident response and reliability: When a critical system fails, analyze application logs, recent code changes, and engineer reports to identify the likely cause and help prepare a fix while the outage is still unfolding.

• Financial research and security: Analyze market signals, assess transactions, and identify suspicious activity while conditions are still changing.

• Customer support and voice: Resolve complex customer issues in real time without interrupting the conversation, even when finding the answer requires multiple steps or systems.

• Commerce: Answer product questions, check inventory, personalize recommendations, and resolve checkout issues while the shopper is still deciding, before hesitation becomes an abandoned cart.

• Live research and experimentation: Turn research that previously took an overnight run into an interactive working session, letting teams test an idea, examine the results, adjust their approach, and run another experiment without breaking their flow.

During the preview period, we’re working with an initial group of customers to understand where this speed makes the biggest difference, and how those learnings can inform our products over time. If your business requires frontier intelligence at the highest speed, you can sign up to get notified when access expands.

GPT‑5.6 Sol Ultrafast and standard build a working 3D warehouse simulator from the same text prompt, side by side.

What early customers are experiencing

We’ve been testing GPT‑5.6 Sol on Ultrafast mode with an initial group of companies across coding, commerce, financial research, support, and other interactive applications. Starting with business workflows lets us study these conditions in real production environments. Their early work is helping us understand where an order-of-magnitude change in speed creates the most value and how products change when the model can keep pace with the person using it. We will use these findings to guide deployment as capacity grows.

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How OpenAI is using Ultrafast

Inside OpenAI, a group of developers has been testing GPT‑5.6 Sol on Ultrafast mode to understand which workflows benefit from frontier intelligence that can answer in real-time.

Incident response is one example where our team is using Ultrafast. When an alert fires, engineers need to build an accurate picture while the system and the evidence are still changing. Teams use it to quickly read logs, analyze traces, synthesize conversations, identify the next checks, and help prepare or validate a fix—all in a fraction of the time with the intelligence of Sol. It reduces the delay between observing a signal, testing a hypothesis, and choosing the next action, while engineers remain responsible for judgment and deployment.

For research, our team uses Ultrafast to rapidly search knowledge sources, query data, and quickly gather, organize, and summarize information across connected tools. A common workflow in research is for our team members to launch a batch of experiments over night, and review the results in the morning. With Ultrafast, we see this loop tightening to support multiple iterations during the workday instead.

Powered by Cerebras

Ultrafast marks the next step in our partnership with Cerebras to bring ultra-low-latency inference to OpenAI’s platform. Now, with GPT‑5.6 Sol on Ultrafast mode, Cerebras is supporting OpenAI’s most intelligent model, delivering up to 750 output tokens per second, enabling businesses to build more responsive products, make faster decisions, and bring powerful AI directly into their most demanding workflows.

Availability

GPT‑5.6 Sol on Ultrafast mode is available in a limited preview today to a select group of customers. We’ll expand access as capacity grows. Sign up for updates.