On October 15, 2026, Microsoft AI CEO Mustafa Suleyman said at an employee meeting that Microsoft's in-house pretrained foundation model MAI-Base-2 outperforms OpenAI's model powering GPT-5.6 Sol, using only a quarter of the training compute and one-twelfth of DeepSeek's compute. Microsoft released the model earlier that day and had privately compared it with several OpenAI models on a confidential basis.