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Model comparison

Claude Fable 5 vs Nemotron 3 Ultra

Data verified

Head-to-head evidence from 23 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.68/100
No comparison
N/A
2 category wins0 category wins

Public leaderboard positions: Claude Fable 5 #2 (Supported); Nemotron 3 Ultra unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Fable 5 and Nemotron 3 Ultra share 23 comparable benchmark results. 2 of 8 categories are comparable. 11 results are unique to Claude Fable 5; 15 to Nemotron 3 Ultra.

Updated July 23, 2026
Shared results
23
Claude Fable 5 only
11
Nemotron 3 Ultra only
15
Comparable categories
2 / 8

Treat this as a split decision. Claude Fable 5 makes more sense if agentic is the priority or you need the larger 1M+ context window; Nemotron 3 Ultra is the better fit if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 23 shared benchmark results across 6 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Fable 5 and Nemotron 3 Ultra finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.

Claude Fable 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Nemotron 3 Ultra. That is roughly Infinityx on output cost alone. Claude Fable 5 gives you the larger context window at 1M+, compared with 1M for Nemotron 3 Ultra.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Fable 5 and Nemotron 3 Ultra
CategoryClaude Fable 5ΔNemotron 3 Ultra
AgenticClaude Fable 584.6Margin← 33.3Nemotron 3 Ultra51.3
CodingClaude Fable 589.2Margin← 30.9Nemotron 3 Ultra58.3
ReasoningClaude Fable 5Not measuredMarginNo overlapNemotron 3 Ultra61.9
KnowledgeClaude Fable 5Not measuredMarginNo overlapNemotron 3 Ultra53.8
MultilingualClaude Fable 5Not measuredMarginNo overlapNemotron 3 Ultra83.0
MultimodalClaude Fable 557.9MarginNo overlapNemotron 3 UltraNot measured
Inst. FollowingClaude Fable 5Not measuredMarginNo overlapNemotron 3 Ultra81.7

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Fable 5B · Nemotron 3 Ultra

  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 84.3%B 56.4%
    Winner: Claude Fable 5Δ 27.9
    Terminal-Bench 2.0: Claude Fable 5 scored 84.3%; Nemotron 3 Ultra scored 56.4%. Claude Fable 5 wins this benchmark.

  2. SWE-bench Verified

    Coding
    Source ↗
    A 95%B 71.9%
    Winner: Claude Fable 5Δ 23.1
    SWE-bench Verified: Claude Fable 5 scored 95%; Nemotron 3 Ultra scored 71.9%. Claude Fable 5 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Fable 5Nemotron 3 UltraComparison
Input / output priceUSD per 1M tokensClaude Fable 5$10 input / $50 outputNemotron 3 Ultra$0 input / $0 outputNemotron 3 Ultra has the lower combined listed price.
Generation speedtokens per secondClaude Fable 5Not availableNemotron 3 UltraNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Fable 5Not availableNemotron 3 UltraNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Fable 51M+Nemotron 3 Ultra1MClaude Fable 5 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Fable 5 wins
BenchmarkClaude Fable 5Nemotron 3 UltraResult
Terminal-Bench 2.0Source 84.3%56.4%Claude Fable 5 leads
OSWorld-VerifiedSource 85%—Not comparable
GDPval-AASource 17481164Claude Fable 5 leads
AA Agentic IndexSource 52.8%27.4%Claude Fable 5 leads
τ²-bench resultsSource 98.5%83.3%Claude Fable 5 leads
GDPval-AASource 62.4%33.2%Claude Fable 5 leads
AA BriefcaseSource 1574870Claude Fable 5 leads
AA AutomationBenchSource 48.6%—Not comparable
AA EnterpriseOps-GymSource 51.1%28.9%Claude Fable 5 leads
AA Harvey LABSource 93.6%81.7%Claude Fable 5 leads
AA Tau3 BankingSource 26.8%—Not comparable
terminalBenchHardSource 62.9%36.4%Claude Fable 5 leads
aaTerminalBench21Source 84.6%—Not comparable
PinchBenchSource —90.0%Not comparable
BrowseCompSource —44.4%Not comparable
τ³-bench resultsSource —70.9%Not comparable
HLE w/ toolsSource —37.4%Not comparable
CodingClaude Fable 5 wins
BenchmarkClaude Fable 5Nemotron 3 UltraResult
SWE-bench VerifiedSource 95%71.9%Claude Fable 5 leads
SWE-bench ProSource 80%—Not comparable
FrontierCode 1.1 MainSource 53.5%—Not comparable
Terminal-Bench 2.0Source 84.3%56.4%Claude Fable 5 leads
cursorBench31Source 70.6%—Not comparable
cursorBench32Source 70.5%—Not comparable
VulcanBench v3Source 87.0%—Not comparable
AA Coding IndexSource 76.5%49.3%Claude Fable 5 leads
AA-SciCodeSource 60.2%39.9%Claude Fable 5 leads
SWE MultilingualSource —67.7%Not comparable
SciCodeSource —44.6%Not comparable
Reasoning
BenchmarkClaude Fable 5Nemotron 3 UltraResult
AA-LCRSource 70.0%67.0%Claude Fable 5 leads
CritPtSource 28.6%3.1%Claude Fable 5 leads
LongBench v2Source —61.9%Not comparable
Knowledge
BenchmarkClaude Fable 5Nemotron 3 UltraResult
Artificial Analysis Intelligence IndexSource 59.9%37.8%Claude Fable 5 leads
AA-GPQA DiamondSource 92.6%86.7%Claude Fable 5 leads
AA-HLESource 53.3%26.6%Claude Fable 5 leads
AA-Omniscience IndexSource 40.2%-0.8%Claude Fable 5 leads
AA-Omniscience AccuracySource 61.4%21.6%Claude Fable 5 leads
AA-Omniscience Hallucination RateSource 54.9%28.5%Nemotron 3 Ultra leads
GPQASource —87%Not comparable
GPQA-DSource —87.0%Not comparable
HLESource —26.7%Not comparable
HLE w/o toolsSource —26.7%Not comparable
MMLU-ProSource —86.8%Not comparable
AA Openness IndexSource —83.3%Not comparable
Multilingual
BenchmarkClaude Fable 5Nemotron 3 UltraResult
MMLU-ProXSource —83%Not comparable
Multimodal
BenchmarkClaude Fable 5Nemotron 3 UltraResult
Blueprint-Bench 2Source 38.6%—Not comparable
OfficeQA ProSource 57.9%—Not comparable
Design Arena WebsiteSource 13321129Claude Fable 5 leads
Inst. Following
BenchmarkClaude Fable 5Nemotron 3 UltraResult
AA-IFBenchSource 63.5%81.4%Nemotron 3 Ultra leads
IFBenchSource —81.7%Not comparable
Frequently Asked Questions (3)

Which is better, Claude Fable 5 or Nemotron 3 Ultra?

Claude Fable 5 and Nemotron 3 Ultra are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.

Which is better for coding, Claude Fable 5 or Nemotron 3 Ultra?

Claude Fable 5 has the edge for coding in this comparison, averaging 89.2 versus 58.3. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Fable 5 or Nemotron 3 Ultra?

Claude Fable 5 has the edge for agentic tasks in this comparison, averaging 84.6 versus 51.3. Inside this category, AA Briefcase is the benchmark that creates the most daylight between them.

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