OpenAI previewed its GPT-5.6 model family on June 26, 2026, with the flagship variant, called Sol, being deployed in partnership with Cerebras Systems, targeting throughput of up to 750 tokens per second starting in July 2026. Cerebras puts everything on a single silicon wafer, minimizing latency bottlenecks that plague conventional GPU setups. OpenAI and Cerebras formalized a multi-year agreement in January 2026 to deploy 750 megawatts of wafer-scale compute capacity dedicated to low-latency inference tasks, with early analysis projecting performance improvements of up to 15 times compared to conventional GPU clusters. The GPT-5.6 model family includes Sol as the flagship, Terra as the cost-efficient variant, and Luna as the speed-optimized option. GPT-5.6 follows GPT-5.5, which OpenAI released on April 23, 2026. The public release of Sol is pending review by U.S. government agencies, with approvals during the preview period handled on a case-by-case basis.