Model Training

Microsoft unveils MAI-Base-2 MoE with 2.8T total, 80B active parameters: Microsoft unveiled MAI-Base-2, a mixture-of-experts model with 2.8T total and 80B active parameters. It claims 4x-12x more pretraining FLOPs-efficiency than DeepSeek-V4-Pro-Base. Microsoft also cited MAI-Thinking-1, a general-purpose foundation model post-trained on MAI-Base-1 announced in June.

AI Models • Techmeme

StepFun releases open weights for Step 5 Preview, a 600B model with 27B active parameters: StepFun released open weights for its Step 5 Preview model, with 600B total and 27B active parameters and a 1M context window. It published a technical blog describing the model's 92-layer design, sparse grouped-query attention, and long-horizon agent training.

StepFun • Pandaily