Llama 3.1 Nemotron Ultra 253b V1 — Retired model
Llama-3.1-Nemotron-Ultra-253B-v1 is a large language model (LLM) optimized for advanced reasoning, human-interactive chat, retrieval-augmented generation (RAG), and tool-calling tasks. Derived from Meta’s Llama-3.1-405B-Instruct, it has been significantly customized using Neural Architecture Search (NAS), resulting in enhanced efficiency, reduced memory usage, and improved inference latency. The model supports a context length of up to 128K tokens and can operate efficiently on an 8x NVIDIA H100 node. Note: you must include `detailed thinking on` in the system prompt to enable reasoning. Please see [Usage Recommendations](https://huggingface.co/nvidia/Llama-3_1-Nemotron-Ultra-253B-v1#quick-start-and-usage-recommendations) for more.
Technical specifications
Independent benchmarks
Scores below come from Artificial Analysis, an independent third party. BazaarLink does not participate in the testing.
Top 5 — CodingCoding Index leaderboard
?/claude-fable-5-1-xhigh81$10 / $50?/claude-fable-5-1-high79$10 / $50openai/gpt-5-6-sol-xhigh78$4 / $20Frequently Asked Questions
Can I still use the retired Llama 3.1 Nemotron Ultra 253b V1 model?
No. Llama 3.1 Nemotron Ultra 253b V1 has been retired and is retained here only as a historical reference. See the active alternatives linked on this page.
Relay integrity checks
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Related models and links