# Mellum2-12B-A2.5B-Instruct vs Nemotron 3 Ultra

> Side-by-side benchmark comparison for Mellum2-12B-A2.5B-Instruct and Nemotron 3 Ultra across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mellum2-12b-a2-5b-instruct-vs-nemotron-3-ultra
- Last updated: September 4, 2026

- Shared sourced benchmarks: 3
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mellum2-12B-A2.5B-Instruct and Nemotron 3 Ultra share only 3 sourced benchmark rows.

## Summary

- Only 3 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Nemotron 3 Ultra has the larger published context window at 1M.

## Model Snapshot

| Property | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra |
|----------|----------|----------|
| Creator | JetBrains | NVIDIA |
| Type | Open Weight | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 128K | 1M |
| Independent public score (not head-to-head) | null | 40.67 |
| Benchmarks Covered | 6 | 24 |
| Pricing (input/output) | N/A | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Instruct public-lane score: 47.8 (Estimated · #82/151)
- Nemotron 3 Ultra public-lane score: 22.2 (Supported · #150/151)

| Benchmark | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| BFCL v4 | 44.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 56.4% | Coming soon |
| PinchBench | Coming soon | 90.0% | Coming soon |
| BrowseComp | Coming soon | 44.4% | Coming soon |
| τ³-bench results | Coming soon | 70.9% | Coming soon |
| HLE w/ tools | Coming soon | 37.4% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 50.9% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Instruct public-lane score: Coming soon
- Nemotron 3 Ultra public-lane score: 26.9 (Supported · #174/183)

| Benchmark | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 37.2% | 89.0% | Nemotron 3 Ultra |
| SWE-bench Verified | Coming soon | 71.9% | Coming soon |
| SWE Multilingual | Coming soon | 67.7% | Coming soon |
| SciCode | Coming soon | 44.6% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 56.4% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 86.0% | Coming soon |
| SWE-bench (Vals) | Coming soon | 69.0% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Instruct public-lane score: Coming soon
- Nemotron 3 Ultra public-lane score: 48.7 (Unranked · 1 rankable row)

| Benchmark | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 3.1% | Coming soon |
| LongBench v2 | Coming soon | 61.9% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Instruct public-lane score: 48.1 (Estimated · #103/181)
- Nemotron 3 Ultra public-lane score: 45.6 (Estimated · #114/181)

| Benchmark | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | 78.1% | Coming soon | Coming soon |
| GPQA | 40.9% | 87% | Nemotron 3 Ultra |
| GPQA-D | 40.9% | 87.0% | Nemotron 3 Ultra |
| HLE | Coming soon | 26.7% | Coming soon |
| HLE w/o tools | Coming soon | 26.7% | Coming soon |
| MMLU-Pro | Coming soon | 86.8% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 86.1% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 85.8% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Instruct public-lane score: Coming soon
- Nemotron 3 Ultra public-lane score: 88.7 (#28/120)

| Benchmark | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 75.8% | Coming soon | Coming soon |
| IFBench | Coming soon | 81.7% | Coming soon |

### Multilingual

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Instruct public-lane score: Coming soon
- Nemotron 3 Ultra public-lane score: 47.4 (#7/12)

| Benchmark | Mellum2-12B-A2.5B-Instruct | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | Coming soon | 83% | Coming soon |

## FAQ

### Is there enough evidence to pick between Mellum2-12B-A2.5B-Instruct and Nemotron 3 Ultra?

Not yet. The models share only 3 sourced benchmark rows, 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

- [Mellum2-12B-A2.5B-Instruct vs Mellum2-12B-A2.5B-Thinking](/compare/mellum2-12b-a2-5b-instruct-vs-mellum2-12b-a2-5b-thinking)
- [Nemotron 3 Ultra vs Mellum2-12B-A2.5B-Thinking](/compare/mellum2-12b-a2-5b-thinking-vs-nemotron-3-ultra)
- [Mellum2-12B-A2.5B-Instruct vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mellum2-12b-a2-5b-instruct)
- [Nemotron 3 Ultra vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-nemotron-3-ultra)

## Explore More

- [Mellum2-12B-A2.5B-Instruct profile](/models/mellum2-12b-a2-5b-instruct)
- [Nemotron 3 Ultra profile](/models/nemotron-3-ultra)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)