Introducing NVIDIA Nemotron 3 Ultra: The Nemotron 3.x family is here!

This post introduces NVIDIA Nemotron 3 Ultra, a new model architecture that addresses the performance degradation of transformer models in long-running agentic workflows. Nemotron 3 Ultra employs a hybrid architecture, predominantly using Mamba layers instead of pure attention mechanisms. This design choice linearly scales inference cost with context length, contrasting with the quadratic scaling of transformers, thus enabling agents to maintain speed over hundreds of reasoning steps. The model is open-source with open weights, data, and recipes. The post highlights the trade-off: Mamba's state-space approach offers efficient summarization, while a smaller number of attention layers provide precision when needed. This architectural innovation is directly integrated into Baseten's platform, making Nemotron 3 Ultra available for use in agentic applications. Additionally, Nemotron 3.5 ASR and Nemotron 3.5 Content Safety models are now available on Baseten.