nvidia · Open weights
Nvidia Nemotron 3 Ultra 550B
Nvidia's Nemotron 3 Ultra 550B A55B model from the Nemotron 3 family. It uses a hybrid Mamba-Transformer MoE architecture. Provider-specific context limits vary, with the longest current route supporting up to 1M context.
- Reasoning
- Tools
- Parallel tools
- Input
- Text
- Output
- Text
- Discovery tier
- Open weights
Pricing
USD per 1M tokens- Input
- $0.50
- Output
- $2.50
Reference prices as published by the model provider. API example
Specifications
- Context window
- 1M
- Max output
- 65.5K
- Average output (7 days)
- 56 tokens
- Longer than 5% of 465 models
Side by side
Compare models
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Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
Intelligence Index
22.9
Better than 56% of 326 scored models
Indexes
Coding Index
49.3Composite of the coding evaluations
Better than 45% of 168 scored models
Agentic work
AutomationBench-AA
3.0%Workflow automation, penalized for guardrail violations
Better than 18% of 173 scored models
AutomationBench-AA tasks completed
0.3%Workflows finished end to end without a guardrail violation
Better than 19% of 173 scored models
AA-Briefcasev1.1
876 EloAgentic knowledge work, rated head to head
Better than 37% of 166 scored models
GDPval-AAv2.1
1,013 EloEconomically valuable occupational tasks, rated head to head
Better than 36% of 187 scored models
Document reasoning
GDP.pdf
5.0%Professional reasoning over PDF documents, all-pass rate
Better than 21% of 171 scored models
AA-LCRv1.1
79.3%Reasoning across long documents
Better than 73% of 309 scored models
MLCR-AA
5.6%Long-context reasoning over medical records
Better than 18% of 121 scored models
Reasoning and knowledge
Humanity’s Last Exam
28.4%Expert-level questions across academic fields
Better than 59% of 323 scored models
GPQA Diamond
86.7%Graduate-level science questions
Better than 67% of 291 scored models
IFBench
81.4%Following precise output instructions
Better than 98% of 215 scored models
Coding
Terminal-Benchv4.0
0.5%Practical software engineering in a terminal
Better than 30% of 171 scored models
SciCode
40.3%Scientific computing in Python
Better than 22% of 174 scored models
Legacy evaluations
Terminal-Bench Hard
36.4%Earlier terminal task suite
Better than 70% of 212 scored models
τ²-Bench Telecom
83.3%Tool use in a customer-support simulation
Better than 63% of 214 scored models
AA-LCR (unversioned)
79.3%Long-context reasoning, earlier grading
Better than 73% of 309 scored models
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
Live routing data
Performance and reliability
Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.
- Throughput
- 112.4 tok/s
- Faster than 67% of 250 models
- Time to first token
- 1.4 s
- Quicker than 89% of 250 models
- Prompt cache hits
- 10.3%
- Request success (24h)
- 100.0%
- Reliable
Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.
- Healthy (98% or more)
- Degraded (90–98%)
- Down (under 90%)
- No requests
Developers
Use it through the API
Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.
curl https://www.noumen.xyz/api/v1/chat/completions \
-H "Authorization: Bearer $NOUMEN_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "nvidia/nemotron-3-ultra-550b-a55b",
"messages": [{ "role": "user", "content": "Explain this stack trace." }]
}'import os
from openai import OpenAI
client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
model="nvidia/nemotron-3-ultra-550b-a55b",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)nvidia
Related models
Other nvidia models, starting with the same family.