NVIDIA has presented Nemotron 3 Ultra as an open Mixture-of-Experts reasoning model with 550 billion total parameters, 55 billion active parameters, and support for up to a 1 million-token context window. The company says it is releasing pre-trained, post-trained, and quantized checkpoints along with datasets, posit...
NVIDIA has introduced Nemotron 3 Ultra as an open 550-billion-parameter reasoning model aimed at long-context and agentic AI workloads.
According to NVIDIA Research, Nemotron 3 Ultra is a Mixture-of-Experts model with 550 billion total parameters and 55 billion active parameters. NVIDIA says the model supports up to a 1 million-token context window and is being released with pre-trained, post-trained, and quantized checkpoints, as well as datasets.
NVIDIA’s Developer Blog describes Nemotron 3 Ultra as a 550B-parameter Mixture-of-Experts model designed for “frontier reasoning” and long-running agent orchestration. The 55B active-parameter design means only a portion of the full model is used for a given token, a common MoE approach intended to increase capacity while controlling compute requirements at inference time.
The company’s research page emphasizes openness around the release materials. NVIDIA says it is providing multiple checkpoint types, including pre-trained and post-trained versions, alongside quantized variants. That matters for developers and researchers because quantized checkpoints can make very large models more practical to evaluate or deploy on constrained infrastructure, though real-world requirements still depend on serving setup, precision, throughput targets, and context length.
One of NVIDIA’s headline specifications is support for up to a 1 million-token context window. In practical terms, that positions Nemotron 3 Ultra for tasks involving large documents, extended conversations, codebases, or multi-step workflows where retaining more prior information may be useful.
NVIDIA frames the model in relation to long-running agents, a category of systems that can plan, call tools, inspect outputs, and continue working across many steps. The Developer Blog specifically connects Nemotron 3 Ultra to more efficient reasoning for these long-running agent use cases. As with any model release, performance in production will depend on evaluation against the target workload rather than specifications alone.
Digital Applied’s June 5, 2026 release analysis reports that Nemotron 3 Ultra is being discussed in relation to Artificial Analysis benchmark positioning, along with access and pricing considerations. The source describes the model as a 550B MoE open reasoning model with 55B active parameters and a 1M architectural context.
Benchmark rankings can help compare model behavior across standardized tests, but they do not fully capture deployment costs, latency, reliability, tool-use behavior, or domain-specific accuracy. For organizations evaluating Nemotron 3 Ultra, NVIDIA’s checkpoint availability and the availability of quantized versions may be as important as headline scores.
Nemotron 3 Ultra adds another very large open model to a market where frontier-scale systems are often available mainly through hosted APIs. NVIDIA’s stated release of checkpoints and datasets gives researchers and enterprise teams more room to inspect, adapt, or deploy the model under the terms NVIDIA provides.
The model also reflects a broader shift in AI development toward long-context reasoning and agent-oriented systems. NVIDIA is not only presenting Nemotron 3 Ultra as a language model, but as infrastructure for workflows that may need to reason over extended histories and coordinate multiple steps over time.
For now, the clearest verified details are the core specifications reported by NVIDIA Research and NVIDIA’s Developer Blog: 550 billion total parameters, 55 billion active parameters, Mixture-of-Experts architecture, up to 1 million tokens of context, and release materials that include pre-trained, post-trained, and quantized checkpoints plus datasets. Developers considering the model should evaluate it against their own tasks, serving constraints, and cost assumptions before treating benchmark claims as a proxy for production performance.
NVIDIA has introduced Nemotron 3 Ultra as an open 550 billion parameter reasoning model aimed at long context and agentic AI workloads.
According to NVIDIA Research, Nemotron 3 Ultra is a Mixture of Experts model with 550 billion total parameters and 55 billion active parameters.
NVIDIA says the model supports up to a 1 million token context window and is being released with pre trained, post trained, and quantized checkpoints, as well as datasets.
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