Model comparison
GPT-5.1-Codex vs Nemotron 3 Ultra
Head-to-head evidence from 13 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Verified leaderboard positions: GPT-5.1-Codex unranked; Nemotron 3 Ultra #24
BenchAlign evidence: GPT-5.1-Codex estimated; Nemotron 3 Ultra not scored. Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.1-Codex and Nemotron 3 Ultra share 13 comparable benchmark results. 0 of 8 categories are comparable. 4 results are unique to GPT-5.1-Codex; 26 to Nemotron 3 Ultra.
Updated July 16, 2026- Shared results
- 13
- GPT-5.1-Codex only
- 4
- Nemotron 3 Ultra only
- 26
- Comparable categories
- 0 / 8
Benchmark data for GPT-5.1-Codex and Nemotron 3 Ultra is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 13 shared benchmark results across 6 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.
Nemotron 3 Ultra has the larger context window at 1M, compared with 400K for GPT-5.1-Codex.
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 | GPT-5.1-Codex | Δ | Nemotron 3 Ultra |
|---|---|---|---|
| Agentic | GPT-5.1-CodexNot measured | MarginNo overlap | Nemotron 3 Ultra51.3 |
| Coding | GPT-5.1-CodexNot measured | MarginNo overlap | Nemotron 3 Ultra58.3 |
| Reasoning | GPT-5.1-CodexNot measured | MarginNo overlap | Nemotron 3 Ultra61.9 |
| Knowledge | GPT-5.1-CodexNot measured | MarginNo overlap | Nemotron 3 Ultra54.2 |
| Multilingual | GPT-5.1-CodexNot measured | MarginNo overlap | Nemotron 3 Ultra83.0 |
| Inst. Following | GPT-5.1-CodexNot measured | MarginNo overlap | Nemotron 3 Ultra81.7 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.1-Codex | Nemotron 3 Ultra | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.1-CodexNot available | Nemotron 3 Ultra$0 input / $0 output | A complete price comparison is not available. |
| Generation speedtokens per second | GPT-5.1-CodexNot available | Nemotron 3 UltraNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.1-CodexNot available | Nemotron 3 UltraNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.1-Codex400K | Nemotron 3 Ultra1M | Nemotron 3 Ultra lists the larger context window. |
Benchmark Deep Dive
Agentic14 benchmarks
| Benchmark | GPT-5.1-Codex | Nemotron 3 Ultra | Result |
|---|---|---|---|
| τ²-bench resultsSource | 83% | 83.3% | Nemotron 3 Ultra leads |
| Gert LabsSource | 49.68% | — | Not comparable |
| JobBenchSource | 26.2% | — | Not comparable |
| Terminal-Bench 2.0Source | — | 56.4% | Not comparable |
| PinchBenchSource | — | 90.0% | Not comparable |
| BrowseCompSource | — | 44.4% | Not comparable |
| τ³-bench resultsSource | — | 70.9% | Not comparable |
| GDPval-AASource | — | 33.2% | Not comparable |
| HLE w/ toolsSource | — | 37.4% | Not comparable |
| AA Agentic IndexSource | — | 27.4% | Not comparable |
| GDPval-AASource | — | 1164 | Not comparable |
| AA BriefcaseSource | — | 870 | Not comparable |
| AA EnterpriseOps-GymSource | — | 28.9% | Not comparable |
| AA Harvey LABSource | — | 3.3% | Not comparable |
Coding9 benchmarks
| Benchmark | GPT-5.1-Codex | Nemotron 3 Ultra | Result |
|---|---|---|---|
| Vibe Code BenchSource | 13.12% | — | Not comparable |
| Terminal-Bench HardSource | 34.8% | 36.4% | Nemotron 3 Ultra leads |
| AA-SciCodeSource | 40.2% | 39.9% | GPT-5.1-Codex leads |
| SWE-bench VerifiedSource | — | 71.9% | Not comparable |
| SWE MultilingualSource | — | 67.7% | Not comparable |
| LiveCodeBench v6Source | — | 89.0% | Not comparable |
| SciCodeSource | — | 44.6% | Not comparable |
| Terminal-Bench 2.0Source | — | 56.4% | Not comparable |
| AA Coding IndexSource | — | 49.3% | Not comparable |
Reasoning3 benchmarks
Knowledge12 benchmarks
| Benchmark | GPT-5.1-Codex | Nemotron 3 Ultra | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 34.7% | 37.8% | Nemotron 3 Ultra leads |
| AA-GPQA DiamondSource | 86.0% | 86.7% | Nemotron 3 Ultra leads |
| AA-HLESource | 23.4% | 26.6% | Nemotron 3 Ultra leads |
| AA-Omniscience IndexSource | -6.0% | -0.8% | Nemotron 3 Ultra leads |
| AA-Omniscience AccuracySource | 39.2% | 21.6% | GPT-5.1-Codex leads |
| AA-Omniscience Hallucination RateSource | 74.4% | 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 |
Multilingual1 benchmarks
| Benchmark | GPT-5.1-Codex | Nemotron 3 Ultra | Result |
|---|---|---|---|
| MMLU-ProXSource | — | 83% | Not comparable |
Multimodal2 benchmarks
Frequently Asked Questions (3)
Can I compare GPT-5.1-Codex and Nemotron 3 Ultra 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 GPT-5.1-Codex and Nemotron 3 Ultra today?
Nemotron 3 Ultra: $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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