Model comparison
Mellum2-12B-A2.5B-Thinking vs Nemotron 3 Ultra
Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Evidence parity. Mellum2-12B-A2.5B-Thinking and Nemotron 3 Ultra share 2 comparable benchmark results. 2 of 8 categories are comparable. 3 results are unique to Mellum2-12B-A2.5B-Thinking; 36 to Nemotron 3 Ultra.
Updated July 23, 2026- Shared results
- 2
- Mellum2-12B-A2.5B-Thinking only
- 3
- Nemotron 3 Ultra only
- 36
- Comparable categories
- 2 / 8
Treat this as a split decision. Mellum2-12B-A2.5B-Thinking makes more sense if knowledge is the priority; Nemotron 3 Ultra is the better fit if instruction following is the priority or you need the larger 1M context window.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 1 evidence category; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Mellum2-12B-A2.5B-Thinking 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.
Nemotron 3 Ultra gives you the larger context window at 1M, compared with 128K for Mellum2-12B-A2.5B-Thinking.
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 | Mellum2-12B-A2.5B-Thinking | Δ | Nemotron 3 Ultra |
|---|---|---|---|
| Inst. Following | Mellum2-12B-A2.5B-Thinking76.5 | Margin→ 5.2 | Nemotron 3 Ultra81.7 |
| Knowledge | Mellum2-12B-A2.5B-Thinking57.6 | Margin← 3.8 | Nemotron 3 Ultra53.8 |
| Agentic | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Nemotron 3 Ultra51.3 |
| Coding | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Nemotron 3 Ultra58.3 |
| Reasoning | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Nemotron 3 Ultra61.9 |
| Multilingual | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Nemotron 3 Ultra83.0 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
GPQA
KnowledgeA 57.6%B 87%Winner: Nemotron 3 UltraΔ 29.4GPQA: Mellum2-12B-A2.5B-Thinking scored 57.6%; Nemotron 3 Ultra scored 87%. Nemotron 3 Ultra wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Mellum2-12B-A2.5B-Thinking | Nemotron 3 Ultra | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Mellum2-12B-A2.5B-ThinkingNot available | Nemotron 3 Ultra$0 input / $0 output | A complete price comparison is not available. |
| Generation speedtokens per second | Mellum2-12B-A2.5B-ThinkingNot available | Nemotron 3 UltraNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Mellum2-12B-A2.5B-ThinkingNot available | Nemotron 3 UltraNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Mellum2-12B-A2.5B-Thinking128K | Nemotron 3 Ultra1M | Nemotron 3 Ultra lists the larger context window. |
Benchmark Deep Dive
Agentic14 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Nemotron 3 Ultra | Result |
|---|---|---|---|
| BFCL v4Source | 45.6% | — | 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 |
| τ²-bench resultsSource | — | 83.3% | Not comparable |
| GDPval-AASource | — | 1164 | Not comparable |
| AA BriefcaseSource | — | 870 | Not comparable |
| AA EnterpriseOps-GymSource | — | 28.9% | Not comparable |
| AA Harvey LABSource | — | 81.7% | Not comparable |
| terminalBenchHardSource | — | 36.4% | Not comparable |
Coding6 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Nemotron 3 Ultra | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | — | 71.9% | Not comparable |
| SWE MultilingualSource | — | 67.7% | Not comparable |
| SciCodeSource | — | 44.6% | Not comparable |
| Terminal-Bench 2.0Source | — | 56.4% | Not comparable |
| AA Coding IndexSource | — | 49.3% | Not comparable |
| AA-SciCodeSource | — | 39.9% | Not comparable |
Reasoning3 benchmarks
KnowledgeMellum2-12B-A2.5B-Thinking wins13 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Nemotron 3 Ultra | Result |
|---|---|---|---|
| MMLU-ReduxSource | 86.2% | — | Not comparable |
| GPQASource | 57.6% | 87% | Nemotron 3 Ultra leads |
| GPQA-DSource | 57.6% | 87.0% | Nemotron 3 Ultra leads |
| HLESource | — | 26.7% | Not comparable |
| HLE w/o toolsSource | — | 26.7% | Not comparable |
| MMLU-ProSource | — | 86.8% | Not comparable |
| AA-Omniscience AccuracySource | — | 21.6% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 37.8% | Not comparable |
| AA-GPQA DiamondSource | — | 86.7% | Not comparable |
| AA-HLESource | — | 26.6% | Not comparable |
| AA-Omniscience IndexSource | — | -0.8% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 28.5% | Not comparable |
| AA Openness IndexSource | — | 83.3% | Not comparable |
Multilingual1 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Nemotron 3 Ultra | Result |
|---|---|---|---|
| MMLU-ProXSource | — | 83% | Not comparable |
Multimodal1 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Nemotron 3 Ultra | Result |
|---|---|---|---|
| Design Arena WebsiteSource | — | 1129 | Not comparable |
Frequently Asked Questions (3)
Which is better, Mellum2-12B-A2.5B-Thinking or Nemotron 3 Ultra?
Mellum2-12B-A2.5B-Thinking 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 knowledge tasks, Mellum2-12B-A2.5B-Thinking or Nemotron 3 Ultra?
Mellum2-12B-A2.5B-Thinking has the edge for knowledge tasks in this comparison, averaging 57.6 versus 53.8. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Which is better for instruction following, Mellum2-12B-A2.5B-Thinking or Nemotron 3 Ultra?
Nemotron 3 Ultra has the edge for instruction following in this comparison, averaging 81.7 versus 76.5. Mellum2-12B-A2.5B-Thinking stays close enough that the answer can still flip depending on your workload.
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