CorX Labs

Llama-3.1-Nemotron-Ultra-253B

by NVIDIA · United States
Open weightsReasoningTool calling131K context

Llama 3.1 405B pruned to 253B by neural architecture search, then re-trained for reasoning.


Specification

The numbers

Maker
NVIDIA
Released
2025-04
Parameters
253B
Architecture
Dense transformer
Context window
131,072 tokens
Max output
32,768 tokens
Input
Text
Output
Text
Reasoning
Yes
Tool calling
Yes
Knowledge cutoff
Not reported
Licence
NVIDIA Open Model
Availability
Not reported
Weights
Downloadable

Cost

Price per million tokens

Input
$0.60 / M tokens
Output
$1.80 / M tokens
Blended 3:1
$0.900

This model has open weights, so there is no first-party price. The figures above are a representative third-party hosting rate — you can also run it yourself for the cost of the hardware.

Published scores

Benchmarks

Figures published by NVIDIA or taken from a public leaderboard. Row last checked 2026-08.

Llama-3.1-Nemotron-Ultra-253B by capability category, with its rank among models reporting the same tests.
CategoryScore Rank
ReasoningGPQA Diamond76.0%23 of 83 reporting the same tests
MathsAIME 202580.1%31 of 56 reporting the same tests
CodingWriting and repairing real codeNot reported
KnowledgeBreadth of factual recall under exam conditionsNot reported
MultimodalReading charts, diagrams and photographsNot reported
Instruction followingIFEval89.5%4 of 15 reporting the same tests
Human preferenceWhich answer people pick, blindNot reported

A category averages every benchmark in it that Llama-3.1-Nemotron-Ultra-253B reports. The rank counts only models that report the same tests, so it never compares an average over three benchmarks against an average over one.

Every reported test

MMLU-ProKnowledgeNot reportedNo figure published
GPQA DiamondReasoning76%Rank 23 of 83 models reporting
AIME 2025Maths80.1%Rank 31 of 56 models reporting
MATH-500MathsNot reportedNo figure published
SWE-bench VerifiedCodingNot reportedNo figure published
SWE-bench ProCodingNot reportedNo figure published
Terminal-Bench 2.1CodingNot reportedNo figure published
Frontier-Bench v0.1ReasoningNot reportedNo figure published
Terminal-Bench 4.0CodingNot reportedNo figure published
LiveCodeBenchCodingNot reportedNo figure published
HumanEvalCodingNot reportedNo figure published
MMMUMultimodalNot reportedNo figure published
IFEvalInstruction following89.5%Rank 4 of 15 models reporting
LMArena EloHuman preferenceNot reportedNo figure published

Where these numbers come from

Every score on this page is a published figure, taken from the model's own card, system card, technical report or release post, or from a public leaderboard. CorX Labs did not run these evaluations. Most are self-reported by the lab that built the model, which means they were produced under that lab's own choice of prompt, scaffold and number of attempts — so treat them as a starting point for a shortlist, not as a settled ranking.

A score someone other than the model's maker measured is marked Independent and names its measurer. Those are the stronger numbers on this page — an outside harness has no reason to flatter anyone — and there are not many of them.

Where a figure has not been published, the cell reads Not reported rather than an estimate. Nothing here is inferred, interpolated or guessed. Each model records the month its row was last checked. Full method and caveats.

Same maker

Other models from NVIDIA

AI models with context window, price per million tokens and published benchmark scores. Sortable by any column.
Nemotron Nano 9B v2NVIDIANVIDIA131K$0.04$0.1664%72.1%NVIDIA Open Model
Llama-3.3-Nemotron-Super-49BNVIDIANVIDIA131K$0.13$0.4066.7%67.5%NVIDIA Open Model