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arXiv · 2606.15007

Nemotron 3 Ultra: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning

NVIDIA·:·Aaron Blakeman·Aaron Thomas·Aastha Jhunjhunwala·Abhibha Gupta·Abhinav Khattar·Adam Rajfer·Adi Renduchintala·Adil Asif·Aditya Vavre·Adriana Flores Miranda·Ahmad Bilal·Aileen Zaman·Ajay Hotchandani·Akanksha Shukla·Akhiad Bercovich·Aleksander Ficek·Alex Gronskiy·Alex Kondratenko·Alex Steiner·Alex Ye·Alexander Bukharin·Alexandre Milesi·Ali Taghibakhshi·Alice Gatti·Alisa Liu·Alok Kumar·Amar Phanishayee·Ameya Sunil Mahabaleshwarkar·Amir Klein·Amit Zuker·Amnon Geifman·Anahita Bhiwandiwalla·Ananth Subramaniam·Andrea Santilli·Andrew Fulks·Andrew McHarg·Andrew Tao·Andrii Skliar·Anjulie Agrusa·Ankur Srivastava·Ankur Verma·Anna Shors·Anna Warno·Antoni-Joan Solergibert I Llaquet·Arham Mehta·Arkadiusz Nowaczynski·Arti Jain·Ashwath Aithal·Ashwin Poojary·Asif Ahamed·Asit Mishra·Asma Kuriparambil Thekkumpate·Atefeh Sohrabizadeh·Avinash Kaur·Avinash Vem·Ayush Dattagupta·Barath Subramaniam Anandan·Bardiya Sadeghi·Ben Lanir·Benedikt Schifferer·Besmira Nushi·Bilal Kartal·Bill Thiede·Bita Darvish Rouhani·Bo Deng·Bob Schatz·Boris Ginsburg·Boxin Wang·Brad Nemire·Brandon Norick·Brian Dang·Brian Westphal·Brian Yu·Brucek Khailany·Bryan Catanzaro·Carlo del Mundo·Caryln Aarish·Chankyu Lee·Chantal Hwang·Charbel Sakr·Charles Wang·Charlie Truong·Chen Cui·Cheng Cheng·Cheng-Ping Hsieh·Chenghao Zhang·Chenhui Deng·Chintan Patel·Chris Alexiuk·Christian Cosgrove·Christian Munley·Christine Harvey·Christopher Parisien·Chunyang Shen·Coco Li·Collin Neale·Cynthia Gao·Cyril Meurillon

Abstract

We introduce Nemotron 3 Ultra, a 550 billion total and 55 billion active parameter Mixture-of-Experts Hybrid Mamba-Attention language model. We pre-trained Nemotron 3 Ultra on 20 trillion text tokens, then extended the context length to 1M tokens, and post-trained using Supervised Fine Tuning (SFT), Reinforcement Learning (RL), and Multi-teacher On-Policy Distillation (MOPD). Nemotron 3 Ultra is our most capable model yet, employing multiple key technologies - LatentMoE, Multi Token Prediction (MTP), NVFP4 pre-training, multi-environment RLVR, MOPD, and reasoning budget control. Nemotron 3 Ultra achieves up to ~6x higher inference throughput as compared to state-of-the-art publicly available LLMs while attaining on-par accuracy. The state-of-the-art accuracy, high inference throughput, and 1M token context length make Nemotron 3 Ultra ideal for long-running autonomous agentic tasks. We open-source the base, post-trained, and quantized checkpoints, along with the training data and recipe on HuggingFace.

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NVIDIA, :, Aaron Blakeman, Aaron Thomas, Aastha Jhunjhunwala, Abhibha Gupta, Abhinav Khattar, Adam Rajfer, Adi Renduchintala, Adil Asif, Aditya Vavre, Adriana Flores Miranda, Ahmad Bilal, Aileen Zaman, Ajay Hotchandani, Akanksha Shukla, Akhiad Bercovich, Aleksander Ficek, Alex Gronskiy, Alex Kondratenko, Alex Steiner, Alex Ye, Alexander Bukharin, Alexandre Milesi, Ali Taghibakhshi, Alice Gatti, Alisa Liu, Alok Kumar, Amar Phanishayee, Ameya Sunil Mahabaleshwarkar, Amir Klein, Amit Zuker, Amnon Geifman, Anahita Bhiwandiwalla, Ananth Subramaniam, Andrea Santilli, Andrew Fulks, Andrew McHarg, Andrew Tao, Andrii Skliar, Anjulie Agrusa, Ankur Srivastava, Ankur Verma, Anna Shors, Anna Warno, Antoni-Joan Solergibert I Llaquet, Arham Mehta, Arkadiusz Nowaczynski, Arti Jain, Ashwath Aithal, Ashwin Poojary, Asif Ahamed, Asit Mishra, Asma Kuriparambil Thekkumpate, Atefeh Sohrabizadeh, Avinash Kaur, Avinash Vem, Ayush Dattagupta, Barath Subramaniam Anandan, Bardiya Sadeghi, Ben Lanir, Benedikt Schifferer, Besmira Nushi, Bilal Kartal, Bill Thiede, Bita Darvish Rouhani, Bo Deng, Bob Schatz, Boris Ginsburg, Boxin Wang, Brad Nemire, Brandon Norick, Brian Dang, Brian Westphal, Brian Yu, Brucek Khailany, Bryan Catanzaro, Carlo del Mundo, Caryln Aarish, Chankyu Lee, Chantal Hwang, Charbel Sakr, Charles Wang, Charlie Truong, Chen Cui, Cheng Cheng, Cheng-Ping Hsieh, Chenghao Zhang, Chenhui Deng, Chintan Patel, Chris Alexiuk, Christian Cosgrove, Christian Munley, Christine Harvey, Christopher Parisien, Chunyang Shen, Coco Li, Collin Neale, Cynthia Gao, Cyril Meurillon. 2026-06-12. Nemotron 3 Ultra: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning. https://arxiv.org/abs/2606.15007

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