Model comparison
Claude Opus 4.5 Thinking vs Nemotron Ultra 253B
Head-to-head evidence from 11 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Opus 4.5 Thinking #69 (Estimated); Nemotron Ultra 253B #150 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Opus 4.5 Thinking and Nemotron Ultra 253B share 11 comparable benchmark results. 0 of 8 categories are comparable. 5 results are unique to Claude Opus 4.5 Thinking; 0 to Nemotron Ultra 253B.
Updated July 23, 2026- Shared results
- 11
- Claude Opus 4.5 Thinking only
- 5
- Nemotron Ultra 253B only
- 0
- Comparable categories
- 0 / 8
Benchmark data for Claude Opus 4.5 Thinking and Nemotron Ultra 253B is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 11 shared benchmark results across 5 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Claude Opus 4.5 Thinking has the larger context window at 200K, compared with 32K for Nemotron Ultra 253B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Opus 4.5 Thinking | Nemotron Ultra 253B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Opus 4.5 ThinkingNot available | Nemotron Ultra 253B$0 input / $0 output | A complete price comparison is not available. |
| Generation speedtokens per second | Claude Opus 4.5 ThinkingNot available | Nemotron Ultra 253BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Opus 4.5 ThinkingNot available | Nemotron Ultra 253BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Opus 4.5 Thinking200K | Nemotron Ultra 253B32K | Claude Opus 4.5 Thinking lists the larger context window. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Nemotron Ultra 253B | Result |
|---|---|---|---|
| τ²-bench resultsSource | 89.5% | 11.4% | Claude Opus 4.5 Thinking leads |
Coding2 benchmarks
Reasoning2 benchmarks
Knowledge7 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Nemotron Ultra 253B | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 40.8% | 9.1% | Claude Opus 4.5 Thinking leads |
| AA-GPQA DiamondSource | 86.6% | 72.8% | Claude Opus 4.5 Thinking leads |
| AA-HLESource | 28.4% | 8.1% | Claude Opus 4.5 Thinking leads |
| AA-Omniscience IndexSource | 13.3% | -45.5% | Claude Opus 4.5 Thinking leads |
| AA-Omniscience AccuracySource | 45.7% | 19.9% | Claude Opus 4.5 Thinking leads |
| AA-Omniscience Hallucination RateSource | 59.8% | 81.7% | Claude Opus 4.5 Thinking leads |
| AA MMLU-ProSource | 89.5% | — | Not comparable |
Multilingual1 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Nemotron Ultra 253B | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | 91.3% | — | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Nemotron Ultra 253B | Result |
|---|---|---|---|
| AA-IFBenchSource | 58.0% | 38.2% | Claude Opus 4.5 Thinking leads |
Frequently Asked Questions (3)
Can I compare Claude Opus 4.5 Thinking and Nemotron Ultra 253B on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Claude Opus 4.5 Thinking and Nemotron Ultra 253B today?
Nemotron Ultra 253B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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