# Mellum2.1-12B-A2.5B-Thinking vs Nemotron 3 Nano Omni 30B A3B

> Side-by-side benchmark comparison for Mellum2.1-12B-A2.5B-Thinking and Nemotron 3 Nano Omni 30B A3B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mellum2-1-12b-a2-5b-thinking-vs-nemotron-3-nano-omni-30b-a3b
- Last updated: October 8, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mellum2.1-12B-A2.5B-Thinking and Nemotron 3 Nano Omni 30B A3B share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Nemotron 3 Nano Omni 30B A3B has the larger published context window at 256K.

## Model Snapshot

| Property | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B |
|----------|----------|----------|
| Creator | JetBrains | NVIDIA |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 128K | 256K |
| Independent public score (not head-to-head) | null | 30.84 |
| Benchmarks Covered | 7 | 16 |
| Pricing (input/output) | $0.00 / $0.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: Coming soon

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 17.4% | Coming soon | Coming soon |
| OSWorld | Coming soon | 47.4% | Coming soon |
| τ²-bench results | Coming soon | 45.3% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: 16 (Estimated · #130/146)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 82.0% | Coming soon | Coming soon |
| SWE-bench Verified | 47% | Coming soon | Coming soon |
| SWE-bench Pro | 28% | Coming soon | Coming soon |
| LiveCodeBench v5 | Coming soon | 63.2% | Coming soon |
| SciCode | Coming soon | 32% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: 49.5 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: 40.3 (#43/49)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B | Winner |
|-----------|-----------|-----------|--------|
| MMMU | Coming soon | 70.8% | Coming soon |
| MMLongBench-Doc | Coming soon | 57.5% | Coming soon |
| CharXiv | Coming soon | 76.3% | Coming soon |
| ScreenSpot Pro | Coming soon | 57.8% | Coming soon |
| Video-MME (w/o subtitle) | Coming soon | 72.2% | Coming soon |
| AI2D_TEST | Coming soon | 88.5% | Coming soon |
| RefCOCO (avg) | Coming soon | 90.5% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: 31.2 (Supported · #133/174)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | 87.8% | Coming soon | Coming soon |
| GPQA-D | 64.6% | 72.2% | Nemotron 3 Nano Omni 30B A3B |
| MMLU-Pro | Coming soon | 77.3% | Coming soon |
| GPQA | Coming soon | 72.2% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: 72.4 (#62/125)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.6% | Coming soon | Coming soon |
| IFBench | Coming soon | 74.2% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3 Nano Omni 30B A3B public-lane score: Coming soon

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3 Nano Omni 30B A3B | Winner |
|-----------|-----------|-----------|--------|
| AIME 2025 | Coming soon | 82.1% | Coming soon |

## FAQ

### Is there enough evidence to pick between Mellum2.1-12B-A2.5B-Thinking and Nemotron 3 Nano Omni 30B A3B?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

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- [Nemotron 3 Nano Omni 30B A3B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-nemotron-3-nano-omni-30b-a3b)
- [Mellum2.1-12B-A2.5B-Thinking vs GPT-6 Astra](/compare/gpt-6-astra-vs-mellum2-1-12b-a2-5b-thinking)
- [Nemotron 3 Nano Omni 30B A3B vs GPT-6 Astra](/compare/gpt-6-astra-vs-nemotron-3-nano-omni-30b-a3b)

## Explore More

- [Mellum2.1-12B-A2.5B-Thinking profile](/models/mellum2-1-12b-a2-5b-thinking)
- [Nemotron 3 Nano Omni 30B A3B profile](/models/nemotron-3-nano-omni-30b-a3b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)