Claude Fable 5 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 is the stronger all-rounder.Nemotron 3 Ultra 550B A55B is cheaper.
Scores updated · 40 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 software80Claude Fable 58 of 8 tests
- AgentsCarrying out multi-step tasks on its own50Claude Fable 55 of 5 tests
- ReasoningHard problems that need careful thinking50Claude Fable 55 of 5 tests
- FactsGetting facts right instead of making them up21Claude Fable 52 of 3 tests
- MathCompetition and research-level math10Claude Fable 51 of 1 test
- Long documentsFinding answers in very long texts10Claude Fable 51 of 1 test
- Following instructionsDoing exactly what it is asked11Even1 each
Math and long documents 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 pulls ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+43points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+42.8points ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+41.9points ahead
Where Nemotron 3 Ultra 550B A55B pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+33.9points ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+17.9points ahead
Every test, side by side
All 40 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Fable 5
- Terminal-Bench 2.1Claude Fable 5 by 30.784.653.9+30.7
- SWE-bench ProClaude Fable 5 by 30.38049.7+30.3
- Terminal-Bench HardClaude Fable 5 by 26.562.936.4+26.5
- SWE-bench VerifiedClaude Fable 5 by 24.39570.7+24.3
- LiveBench · Agentic CodingClaude Fable 5 by 23.562.238.7+23.5
- SciCodeClaude Fable 5 by 20.76140.3+20.7
- SWE-bench MultilingualClaude Fable 5 by 18.986.667.7+18.9
- LiveBench · CodingClaude Fable 5 by 15.38670.7+15.3
AgentsClaude Fable 5
- BrowseCompClaude Fable 5 by 4387.444.4+43
- Terminal-Bench 4.0Claude Fable 5 by 41.942.40.5+41.9
- MCP AtlasClaude Fable 5 by 4084.744.7+40
- GDPValClaude Fable 5 by 29.855.525.7+29.8
- τ-Bench V3 · BankingClaude Fable 5 by 23.938.114.2+23.9
ReasoningClaude Fable 5
- SimpleBenchClaude Fable 5 by 40.281.941.7+40.2
- Humanity's Last ExamClaude Fable 5 by 27.155.528.4+27.1
- CritPtClaude Fable 5 by 25.528.63.1+25.5
- LiveBench · ReasoningClaude Fable 5 by 1589.774.7+15
- GPQA DiamondClaude Fable 5 by 5.992.686.7+5.9
FactsClaude Fable 5
- AA-Omniscience · AccuracyClaude Fable 5 by 42.865.322.6+42.8
- SimpleQA VerifiedClaude Fable 5 by 38.370.732.4+38.3
- AA-Omniscience · Non-hallucinationNemotron 3 Ultra 550B A55B by 33.936.470.3+33.9
Following instructionsEven
- IFBenchNemotron 3 Ultra 550B A55B by 17.963.581.4+17.9
- LiveBench · Instruction FollowingClaude Fable 5 by 2.375.873.5+2.3
Other results15 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 by 575 rating points17231148+575 rating
- AA-OmniscienceClaude Fable 5 by 43.743.3-0.4+43.7
- Toolathlon VerifiedClaude Fable 5 by 43.677.934.3+43.6
- SWEBench Pro PublicClaude Fable 5 by 33.68046.4+33.6
- AA Agentic IndexClaude Fable 5 by 29.35121.7+29.3
- Artificial Analysis Coding IndexClaude Fable 5 by 27.276.549.3+27.2
- AA IntelligenceClaude Fable 5 by 26.749.622.9+26.7
- HLE (with tools)Claude Fable 5 by 26.463.837.4+26.4
- livebench_data_analysisClaude Fable 5 by 2680.554.5+26
- livebench_languageClaude Fable 5 by 19.990.770.8+19.9
- Finance Agent v2Claude Fable 5 by 18.856.337.5+18.8
- τ²-Bench Telecom (AA run)Claude Fable 5 by 15.298.583.3+15.2
- τ³-Bench BankingClaude Fable 5 by 8.426.818.4+8.4
- Global-MMLU-LiteClaude Fable 5 by 7.793.385.6+7.7
- StrongREJECTtie98.798.7tie
Questions people ask
Which is better, Claude Fable 5 or Nemotron 3 Ultra 550B A55B?
Claude Fable 5 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. It wins 8 of the 8 coding tests both models report; Nemotron 3 Ultra 550B A55B wins none.
Which is cheaper?
Claude Fable 5 costs $10.00 per million input tokens and $50.00 per million output tokens; Nemotron 3 Ultra 550B A55B costs $0.60 and $2.50. That makes Nemotron 3 Ultra 550B A55B about 95% cheaper for the same work.
How do you compare the two?
We use the 40 benchmark tests both models have published scores on. The verdict counts the 25 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 15 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.