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Nemotron 3 Ultra: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning
Authors:
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
, et al. (549 additional authors not shown)
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 o…
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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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Submitted 12 June, 2026;
originally announced June 2026.
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Accelerating RL Post-Training Rollouts via System-Integrated Speculative Decoding
Authors:
Hayate Iso,
Tiyasa Mitra,
Sudipta Mondal,
Rasoul Shafipour,
Venmugil Elango,
Terry Kong,
Yuki Huang,
Seonjin Na,
Izzy Putterman,
Benjamin Chislett,
Maor Ashkenazi,
Joseph Guman,
Gerald Shen,
Tugrul Konuk,
Ashwath Aithal,
Ritika Borkar,
Ran Zilberstein,
Bita Rouhani
Abstract:
RL post-training of frontier language models is increasingly bottlenecked by autoregressive rollout generation, making rollout acceleration a central systems challenge. Many existing efficiency methods improve throughput by changing the rollout or optimization regime, for example, through off-policy execution, replay, or lower-precision generation. We study speculative decoding as a lossless accel…
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RL post-training of frontier language models is increasingly bottlenecked by autoregressive rollout generation, making rollout acceleration a central systems challenge. Many existing efficiency methods improve throughput by changing the rollout or optimization regime, for example, through off-policy execution, replay, or lower-precision generation. We study speculative decoding as a lossless acceleration primitive for RL rollouts that preserves the target model's output distribution. We implement speculative decoding in NeMo-RL with a vLLM backend, supporting both synchronous and asynchronous pipelines and enabling speculation during RL rollouts. This benefit is realizable across speculation mechanisms, such as pretrained MTP heads, small external draft models or even techniques such as Eagle3, which are traditionally applied after RL phase. This yields a deployment path for state-of-the-art speculative decoding inside RL training. In a reasoning post-training workload at 8B scale under synchronous RL, speculative decoding improves rollout throughput by 1.8x. Using a high-fidelity performance simulator, we project that combining speculative decoding with asynchronous RL yields up to 2.5x end-to-end training speedup at 235B scale.
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Submitted 29 April, 2026;
originally announced April 2026.
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Nemotron 3 Super: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning
Authors:
NVIDIA,
:,
Aakshita Chandiramani,
Aaron Blakeman,
Abdullahi Olaoye,
Abhibha Gupta,
Abhilash Somasamudramath,
Abhinav Khattar,
Adeola Adesoba,
Adi Renduchintala,
Adil Asif,
Aditya Agrawal,
Aditya Vavre,
Ahmad Kiswani,
Aishwarya Padmakumar,
Ajay Hotchandani,
Akanksha Shukla,
Akhiad Bercovich,
Aleksander Ficek,
Aleksandr Shaposhnikov,
Alex Gronskiy,
Alex Kondratenko,
Alex Neefus,
Alex Steiner,
Alex Yang
, et al. (522 additional authors not shown)
Abstract:
We describe the pre-training, post-training, and quantization of Nemotron 3 Super, a 120 billion (active 12 billion) parameter hybrid Mamba-Attention Mixture-of-Experts model. Nemotron 3 Super is the first model in the Nemotron 3 family to 1) be pre-trained in NVFP4, 2) leverage LatentMoE, a new Mixture-of-Experts architecture that optimizes for both accuracy per FLOP and accuracy per parameter, a…
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We describe the pre-training, post-training, and quantization of Nemotron 3 Super, a 120 billion (active 12 billion) parameter hybrid Mamba-Attention Mixture-of-Experts model. Nemotron 3 Super is the first model in the Nemotron 3 family to 1) be pre-trained in NVFP4, 2) leverage LatentMoE, a new Mixture-of-Experts architecture that optimizes for both accuracy per FLOP and accuracy per parameter, and 3) include MTP layers for inference acceleration through native speculative decoding. We pre-trained Nemotron 3 Super on 25 trillion tokens followed by post-training using supervised fine tuning (SFT) and reinforcement learning (RL). The final model supports up to 1M context length and achieves comparable accuracy on common benchmarks, while also achieving up to 2.2x and 7.5x higher inference throughput compared to GPT-OSS-120B and Qwen3.5-122B, respectively. Nemotron 3 Super datasets, along with the base, post-trained, and quantized checkpoints, are open-sourced on HuggingFace.
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Submitted 14 April, 2026;
originally announced April 2026.
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LatentMoE: Toward Optimal Accuracy per FLOP and Parameter in Mixture of Experts
Authors:
Venmugil Elango,
Nidhi Bhatia,
Roger Waleffe,
Rasoul Shafipour,
Tomer Asida,
Abhinav Khattar,
Nave Assaf,
Maximilian Golub,
Joey Guman,
Tiyasa Mitra,
Ritchie Zhao,
Ritika Borkar,
Ran Zilberstein,
Mostofa Patwary,
Mohammad Shoeybi,
Bita Rouhani
Abstract:
Mixture of Experts (MoEs) have become a central component of many state-of-the-art open-source and proprietary large language models. Despite their widespread adoption, it remains unclear how close existing MoE architectures are to optimal with respect to inference cost, as measured by accuracy per floating-point operation and per parameter. In this work, we revisit MoE design from a hardware-soft…
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Mixture of Experts (MoEs) have become a central component of many state-of-the-art open-source and proprietary large language models. Despite their widespread adoption, it remains unclear how close existing MoE architectures are to optimal with respect to inference cost, as measured by accuracy per floating-point operation and per parameter. In this work, we revisit MoE design from a hardware-software co-design perspective, grounded in empirical and theoretical considerations. We characterize key performance bottlenecks across diverse deployment regimes, spanning offline high-throughput execution and online, latency-critical inference. Guided by these insights, we introduce LatentMoE, a new model architecture resulting from systematic design exploration and optimized for maximal accuracy per unit of compute. Empirical design space exploration at scales of up to 95B parameters and over a 1T-token training horizon, together with supporting theoretical analysis, shows that LatentMoE consistently outperforms standard MoE architectures in terms of accuracy per FLOP and per parameter. Given its strong performance, the LatentMoE architecture has been adopted by the flagship Nemotron-3 Super and Ultra models and scaled to substantially larger regimes, including longer token horizons and larger model sizes, as reported in Nvidia et al. (arXiv:2512.20856).
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Submitted 25 January, 2026;
originally announced January 2026.
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NVIDIA Nemotron 3: Efficient and Open Intelligence
Authors:
NVIDIA,
:,
Aaron Blakeman,
Aaron Grattafiori,
Aarti Basant,
Abhibha Gupta,
Abhinav Khattar,
Adi Renduchintala,
Aditya Vavre,
Akanksha Shukla,
Akhiad Bercovich,
Aleksander Ficek,
Aleksandr Shaposhnikov,
Alex Kondratenko,
Alexander Bukharin,
Alexandre Milesi,
Ali Taghibakhshi,
Alisa Liu,
Amelia Barton,
Ameya Sunil Mahabaleshwarkar,
Amir Klein,
Amit Zuker,
Amnon Geifman,
Amy Shen,
Anahita Bhiwandiwalla
, et al. (334 additional authors not shown)
Abstract:
We introduce the Nemotron 3 family of models - Nano, Super, and Ultra. These models deliver strong agentic, reasoning, and conversational capabilities. The Nemotron 3 family uses a Mixture-of-Experts hybrid Mamba-Transformer architecture to provide best-in-class throughput and context lengths of up to 1M tokens. Super and Ultra models are trained with NVFP4 and incorporate LatentMoE, a novel appro…
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We introduce the Nemotron 3 family of models - Nano, Super, and Ultra. These models deliver strong agentic, reasoning, and conversational capabilities. The Nemotron 3 family uses a Mixture-of-Experts hybrid Mamba-Transformer architecture to provide best-in-class throughput and context lengths of up to 1M tokens. Super and Ultra models are trained with NVFP4 and incorporate LatentMoE, a novel approach that improves model quality. The two larger models also include MTP layers for faster text generation. All Nemotron 3 models are post-trained using multi-environment reinforcement learning enabling reasoning, multi-step tool use, and support granular reasoning budget control. Nano, the smallest model, outperforms comparable models in accuracy while remaining extremely cost-efficient for inference. Super is optimized for collaborative agents and high-volume workloads such as IT ticket automation. Ultra, the largest model, provides state-of-the-art accuracy and reasoning performance. Nano is released together with its technical report and this white paper, while Super and Ultra will follow in the coming months. We will openly release the model weights, pre- and post-training software, recipes, and all data for which we hold redistribution rights.
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Submitted 23 December, 2025;
originally announced December 2025.
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Nemotron 3 Nano: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning
Authors:
NVIDIA,
:,
Aaron Blakeman,
Aaron Grattafiori,
Aarti Basant,
Abhibha Gupta,
Abhinav Khattar,
Adi Renduchintala,
Aditya Vavre,
Akanksha Shukla,
Akhiad Bercovich,
Aleksander Ficek,
Aleksandr Shaposhnikov,
Alex Kondratenko,
Alexander Bukharin,
Alexandre Milesi,
Ali Taghibakhshi,
Alisa Liu,
Amelia Barton,
Ameya Sunil Mahabaleshwarkar,
Amir Klein,
Amit Zuker,
Amnon Geifman,
Amy Shen,
Anahita Bhiwandiwalla
, et al. (289 additional authors not shown)
Abstract:
We present Nemotron 3 Nano 30B-A3B, a Mixture-of-Experts hybrid Mamba-Transformer language model. Nemotron 3 Nano was pretrained on 25 trillion text tokens, including more than 3 trillion new unique tokens over Nemotron 2, followed by supervised fine tuning and large-scale RL on diverse environments. Nemotron 3 Nano achieves better accuracy than our previous generation Nemotron 2 Nano while activa…
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We present Nemotron 3 Nano 30B-A3B, a Mixture-of-Experts hybrid Mamba-Transformer language model. Nemotron 3 Nano was pretrained on 25 trillion text tokens, including more than 3 trillion new unique tokens over Nemotron 2, followed by supervised fine tuning and large-scale RL on diverse environments. Nemotron 3 Nano achieves better accuracy than our previous generation Nemotron 2 Nano while activating less than half of the parameters per forward pass. It achieves up to 3.3x higher inference throughput than similarly-sized open models like GPT-OSS-20B and Qwen3-30B-A3B-Thinking-2507, while also being more accurate on popular benchmarks. Nemotron 3 Nano demonstrates enhanced agentic, reasoning, and chat abilities and supports context lengths up to 1M tokens. We release both our pretrained Nemotron 3 Nano 30B-A3B Base and post-trained Nemotron 3 Nano 30B-A3B checkpoints on Hugging Face.
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Submitted 23 December, 2025;
originally announced December 2025.
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On the Duality of Task and Actor Programming Models
Authors:
Rohan Yadav,
Joseph Guman,
Sean Treichler,
Michael Garland,
Alex Aiken,
Fredrik Kjolstad,
Michael Bauer
Abstract:
Programming models for distributed and heterogeneous machines are rapidly growing in popularity to meet the demands of modern workloads. Task and actor models are common choices that offer different trade-offs between development productivity and achieved performance. Task-based models offer better productivity and composition of software, whereas actor-based models routinely deliver better peak p…
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Programming models for distributed and heterogeneous machines are rapidly growing in popularity to meet the demands of modern workloads. Task and actor models are common choices that offer different trade-offs between development productivity and achieved performance. Task-based models offer better productivity and composition of software, whereas actor-based models routinely deliver better peak performance due to lower overheads. While task-based and actor-based models appear to be different superficially, we demonstrate these programming models are duals of each other. Importantly, we show that this duality extends beyond functionality to performance, and elucidate techniques that let task-based systems deliver performance competitive with actor-based systems without compromising productivity. We apply these techniques to both Realm, an explicitly parallel task-based runtime, as well as Legion, an implicitly parallel task-based runtime. We show these techniques reduce Realm's overheads by between 1.7-5.3x, coming within a factor of two of the overheads imposed by heavily optimized actor-based systems like Charm++ and MPI. We further show that our techniques enable between 1.3-5.0x improved strong scaling of unmodified Legion applications.
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Submitted 22 August, 2025;
originally announced August 2025.