o3-mini vs Nemotron Ultra 253B

Side-by-side benchmark comparison across knowledge, coding, math, and reasoning.

o3-mini is clearly ahead on the aggregate, 56 to 50. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

o3-mini's sharpest advantage is in knowledge, where it averages 82.1 against 43.5. The single biggest benchmark swing on the page is MMLU, 86.9 to 49.

o3-mini gives you the larger context window at 200K, compared with 32K for Nemotron Ultra 253B.

Quick Verdict

Pick o3-mini if you want the stronger benchmark profile. Nemotron Ultra 253B only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.

Knowledge

o3-mini

o3-mini

82.1

Nemotron Ultra 253B

43.5

86.9
MMLU
49
77.2
GPQA
48
-
SuperGPQA
46
-
OpenBookQA
44
-
MMLU-Pro
63
-
HLE
11

Coding

o3-mini

o3-mini

49.3

Nemotron Ultra 253B

34

49.3
SWE-bench Verified
31
-
HumanEval
41
-
LiveCodeBench
30

Mathematics

o3-mini

o3-mini

87.3

Nemotron Ultra 253B

51.3

87.3
AIME 2024
51
-
AIME 2023
49
-
AIME 2025
50
-
HMMT Feb 2023
45
-
HMMT Feb 2024
47
-
HMMT Feb 2025
46
-
BRUMO 2025
48
-
MATH-500
74

Reasoning

Nemotron Ultra 253B
-
SimpleQA
47
-
MuSR
45
-
BBH
77

Instruction Following

o3-mini

o3-mini

93.9

Nemotron Ultra 253B

78

93.9
IFEval
78

Multilingual

Nemotron Ultra 253B
-
MGSM
74

Frequently Asked Questions

Which is better, o3-mini or Nemotron Ultra 253B?

o3-mini is ahead overall, 56 to 50. The biggest single separator in this matchup is MMLU, where the scores are 86.9 and 49.

Which is better for knowledge tasks, o3-mini or Nemotron Ultra 253B?

o3-mini has the edge for knowledge tasks in this comparison, averaging 82.1 versus 43.5. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, o3-mini or Nemotron Ultra 253B?

o3-mini has the edge for coding in this comparison, averaging 49.3 versus 34. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, o3-mini or Nemotron Ultra 253B?

o3-mini has the edge for math in this comparison, averaging 87.3 versus 51.3. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for instruction following, o3-mini or Nemotron Ultra 253B?

o3-mini has the edge for instruction following in this comparison, averaging 93.9 versus 78. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

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