NVIDIA's Nemotron 3 Ultra Reaches 47.7 on Artificial Analysis Intelligence Index, Leading US Open-Weights Models

NVIDIA has released Nemotron 3 Ultra, a 550-billion-parameter open-weights model that scores 47.7 on the Artificial Analysis Intelligence Index, establishing itself as the most capable US open-source large language model available. The model achieves this through a hybrid Mamba-Transformer architecture with expert routing, combining sequence efficiency for long-context reasoning with precise fact recall—a design that delivers 5× higher throughput and approximately 30% cost reduction compared to comparable open models.