Forty Four on the Index, One Fifth the Price: StepFun's Six Hundred Billion Parameter Bid at the Frontier, September 20, 2026

Forty Four on the Index, One Fifth the Price: StepFun's Six Hundred Billion Parameter Bid at the Frontier, September 20, 2026 Shanghai startup StepFun released Step 5 Preview, a six hundred billion parameter sparse mixture of experts model that ties Kimi K3 on the Artificial Analysis Intelligence Index while charging less than a fifth of the output price. Rick Spair and Laura dig into the architecture, the benchmark numbers, the verbosity problem hiding behind that attractive per token price...