Noometry

Model comparison

Grok 4 Fast vs Nemotron 3 Ultra

Nemotron 3 Ultra is the stronger model overall, scoring 42.5 to 39.4 on the Noometry Index.

Last verified . 19 shared benchmarks.

Grok 4 Fast xAI

39.4

Rank #167 Confirmed

Nemotron 3 Ultra NVIDIA

42.5

Rank #113 Confirmed

Summary

  • They share 19 benchmarks with published results for both. Grok 4 Fast scores higher in 3 categories and Nemotron 3 Ultra in 6 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Nemotron 3 Ultra leads 52.5 to 32.0.
  • The biggest single-benchmark swing is DTBench: 82.7% for Grok 4 Fast and 90.1% for Nemotron 3 Ultra.
  • Nemotron 3 Ultra has downloadable open weights; the other is API-only.

Side by side

Grok 4 FastNemotron 3 Ultra
ProviderxAINVIDIA
Noometry Index39.442.5
Released2025-09-192026-06-04
WeightsProprietaryOpen
Context window—262K
Max output—128K
Input $ / M tokens—$0.60
Output $ / M tokens—$2.40
Results tracked3030

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Category by category

Coding Nemotron 3 Ultra leads

Grok 4 Fast: 32.5 (#271), Nemotron 3 Ultra: 38.1 (#182)

BenchmarkGrok 4 FastNemotron 3 Ultra
WeirdML42.9%43.5%
LMArena Coding14291468
FrontierCode—13.6%
LMArena WebDev1159—
SciCode—40.3%

Agentic & Tool Use Grok 4 Fast leads

Grok 4 Fast: 29.5 (#86), Nemotron 3 Ultra: 23.4 (#126)

BenchmarkGrok 4 FastNemotron 3 Ultra
APEX-Agents—22.7%
τ²-bench Banking15.7%—
Cybench30%—
LMArena Search1171—

Reasoning Nemotron 3 Ultra leads

Grok 4 Fast: 22.2 (#201), Nemotron 3 Ultra: 31.0 (#82)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Hard Prompts14121452
DTBench82.7%90.1%
Epoch Capabilities Index144.2146.17
ARC-AGI-25.3%—
Kagi LLM Benchmark66.1%—
ARC-AGI-148.5%—
CritPt—3.1%
Chess Puzzles—12%
Mystery Game Puzzles—20%
LMCA—36.9%
ForecastBench60.5—

Math Grok 4 Fast leads

Grok 4 Fast: 38.9 (#123), Nemotron 3 Ultra: 35.3 (#187)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Math14191457
OTIS Mock AIME 2024-2025—86.7%
ProofBench—2%

Knowledge Nemotron 3 Ultra leads

Grok 4 Fast: 32.0 (#214), Nemotron 3 Ultra: 52.5 (#61)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Expert14111472
GPQA Diamond—85.4%
Vectara Hallucination Rate19.7%—

Multilingual Nemotron 3 Ultra leads

Grok 4 Fast: 51.3 (#111), Nemotron 3 Ultra: 53.5 (#64)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Non-English13961427
LMArena Chinese14571497
LMArena French14311472
LMArena German13831471
LMArena Korean13571386
LMArena Russian13891417
LMArena Spanish14151454
LMArena Japanese1352—

Instruction Following Nemotron 3 Ultra leads

Grok 4 Fast: 73.2 (#121), Nemotron 3 Ultra: 74.7 (#88)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Instruction Following13871418

Long Context Grok 4 Fast leads

Grok 4 Fast: 63.2 (#3), Nemotron 3 Ultra: 43.9 (#81)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Longer Query14151437
Fiction.LiveBench94.4%—

Writing & Preference Nemotron 3 Ultra leads

Grok 4 Fast: 60.0 (#102), Nemotron 3 Ultra: 66.3 (#36)

BenchmarkGrok 4 FastNemotron 3 Ultra
LMArena Text14071445
LMArena Creative Writing13871398
LMArena Multi-Turn14141411
EQ-Bench Creative Writing—1692

Frequently asked questions

Is Grok 4 Fast better than Nemotron 3 Ultra?

Nemotron 3 Ultra is the stronger model overall, scoring 42.5 to 39.4 on the Noometry Index.

Is Grok 4 Fast or Nemotron 3 Ultra better for coding?

Nemotron 3 Ultra scores higher on coding benchmarks: 38.1 versus 32.5 in the Noometry coding category.

How many benchmarks do Grok 4 Fast and Nemotron 3 Ultra share?

19 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Nemotron 3 Ultra has 30.

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