Claude Fable 5.1 vs Nemotron 3 Ultra 550B A55B
Wins 6 of 7 areas
Coding · Agents · Reasoning · Facts · Math · Long documents
Wins 0 of 7 areas
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Claude Fable 5.1 is the stronger all-rounder.Nemotron 3 Ultra 550B A55B is cheaper.
Scores updated · 29 tests both models report · How we compare
Where each one wins
Tests won in each of the seven areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- CodingWriting and fixing software60Claude Fable 5.16 of 6 tests
- ReasoningHard problems that need careful thinking50Claude Fable 5.15 of 5 tests
- AgentsCarrying out multi-step tasks on its own30Claude Fable 5.13 of 3 tests
- FactsGetting facts right instead of making them up21Claude Fable 5.12 of 3 tests
- MathCompetition and research-level math10Claude Fable 5.11 of 1 test
- Long documentsFinding answers in very long texts10Claude Fable 5.11 of 1 test
- Following instructionsDoing exactly what it is asked00Even0 each · 1 tie
Math, long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Nemotron 3 Ultra 550B A55B costs 95% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Fable 5.1 pulls ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+51.5points ahead
- Common-sense trick questionsSimpleBench+44.9points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+44.6points ahead
Where Nemotron 3 Ultra 550B A55B pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+42.9points ahead
Every test, side by side
All 29 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Fable 5.1
- Terminal-Bench 2.1Claude Fable 5.1 by 37.591.453.9+37.5
- SWE-bench ProClaude Fable 5.1 by 31.581.249.7+31.5
- LiveBench · Agentic CodingClaude Fable 5.1 by 27.466.138.7+27.4
- SciCodeClaude Fable 5.1 by 22.863.140.3+22.8
- SWE-bench MultilingualClaude Fable 5.1 by 21.489.167.7+21.4
- LiveBench · CodingClaude Fable 5.1 by 15.786.470.7+15.7
AgentsClaude Fable 5.1
- Terminal-Bench 4.0Claude Fable 5.1 by 51.5520.5+51.5
- GDPValClaude Fable 5.1 by 3762.725.7+37
- τ-Bench V3 · BankingClaude Fable 5.1 by 3347.214.2+33
ReasoningClaude Fable 5.1
- SimpleBenchClaude Fable 5.1 by 44.986.641.7+44.9
- Humanity's Last ExamClaude Fable 5.1 by 30.759.128.4+30.7
- CritPtClaude Fable 5.1 by 26.629.73.1+26.6
- LiveBench · ReasoningClaude Fable 5.1 by 1791.774.7+17
- GPQA DiamondClaude Fable 5.1 by 793.786.7+7
FactsClaude Fable 5.1
- AA-Omniscience · AccuracyClaude Fable 5.1 by 44.667.222.6+44.6
- AA-Omniscience · Non-hallucinationNemotron 3 Ultra 550B A55B by 42.927.470.3+42.9
- SimpleQA VerifiedClaude Fable 5.1 by 38.470.832.4+38.4
Following instructionsEven
- LiveBench · Instruction Followingtie7373.5tie
Other results9 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- GDPval-AA v2Claude Fable 5.1 by 687 rating points18351148+687 rating
- AA-OmniscienceClaude Fable 5.1 by 43.943.5-0.4+43.9
- Toolathlon VerifiedClaude Fable 5.1 by 43.577.834.3+43.5
- AA Agentic IndexClaude Fable 5.1 by 36.35821.7+36.3
- Artificial Analysis Coding IndexClaude Fable 5.1 by 32.381.649.3+32.3
- AA IntelligenceClaude Fable 5.1 by 30.553.422.9+30.5
- HLE (with tools)Claude Fable 5.1 by 28.265.637.4+28.2
- livebench_data_analysisClaude Fable 5.1 by 25.880.354.5+25.8
- livebench_languageClaude Fable 5.1 by 18.789.570.8+18.7
Questions people ask
Which is better, Claude Fable 5.1 or Nemotron 3 Ultra 550B A55B?
Claude Fable 5.1 wins six of the seven areas where both have results: coding, agents, reasoning, facts, math and long documents. Nemotron 3 Ultra 550B A55B wins none, but costs 95% less. They are level on following instructions.
Which is better for coding?
Claude Fable 5.1. It wins 6 of the 6 coding tests both models report; Nemotron 3 Ultra 550B A55B wins none.
Which is cheaper?
Claude Fable 5.1 costs $10.00 per million input tokens and $50.00 per million output tokens; Nemotron 3 Ultra 550B A55B costs $0.60 and $2.70. That makes Nemotron 3 Ultra 550B A55B about 95% cheaper for the same work.
How do you compare the two?
We use the 29 benchmark tests both models have published scores on. The verdict counts the 20 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 9 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.