# Mellum2.1-12B-A2.5B-Thinking vs Nemotron 3.5 Lightning 30B A3B NVFP4

> Side-by-side benchmark comparison for Mellum2.1-12B-A2.5B-Thinking and Nemotron 3.5 Lightning 30B A3B NVFP4 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mellum2-1-12b-a2-5b-thinking-vs-nemotron-3-5-lightning-30b-a3b-nvfp4
- Last updated: October 8, 2026

- Shared sourced benchmarks: 3
- 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 3.5 Lightning 30B A3B NVFP4 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 3.5 Lightning 30B A3B NVFP4 has the larger published context window at 1M.

## Model Snapshot

| Property | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3.5 Lightning 30B A3B NVFP4 |
|----------|----------|----------|
| Creator | JetBrains | NVIDIA |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 128K | 1M |
| Independent public score (not head-to-head) | null | 22.31 |
| Benchmarks Covered | 7 | 13 |
| 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 3.5 Lightning 30B A3B NVFP4 public-lane score: 11.6 (Estimated · #113/122)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3.5 Lightning 30B A3B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 17.4% | 23.5% | Nemotron 3.5 Lightning 30B A3B NVFP4 |
| PinchBench | Coming soon | 83.4% | Coming soon |
| BrowseComp | Coming soon | 36.8% | Coming soon |
| τ³-bench results | Coming soon | 9.5% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3.5 Lightning 30B A3B NVFP4 public-lane score: 13.1 (Estimated · #134/146)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3.5 Lightning 30B A3B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 82.0% | Coming soon | Coming soon |
| SWE-bench Verified | 47% | 52.8% | Nemotron 3.5 Lightning 30B A3B NVFP4 |
| SWE-bench Pro | 28% | Coming soon | Coming soon |
| SWE Multilingual | Coming soon | 36.5% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 23.5% | Coming soon |
| SciCode | Coming soon | 31.4% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3.5 Lightning 30B A3B NVFP4 public-lane score: 56 (Unranked · 1 rankable row)

### Knowledge

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3.5 Lightning 30B A3B NVFP4 public-lane score: 24.8 (Estimated · #161/174)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3.5 Lightning 30B A3B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | 87.8% | Coming soon | Coming soon |
| GPQA-D | 64.6% | 75.6% | Nemotron 3.5 Lightning 30B A3B NVFP4 |
| GPQA | Coming soon | 75.6% | Coming soon |
| HLE w/o tools | Coming soon | 10.5% | Coming soon |
| MMLU-Pro | Coming soon | 81.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Nemotron 3.5 Lightning 30B A3B NVFP4 public-lane score: 67.8 (#67/125)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Nemotron 3.5 Lightning 30B A3B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.6% | Coming soon | Coming soon |
| IFBench | Coming soon | 72.9% | Coming soon |

## FAQ

### Is there enough evidence to pick between Mellum2.1-12B-A2.5B-Thinking and Nemotron 3.5 Lightning 30B A3B NVFP4?

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

- [Mellum2.1-12B-A2.5B-Thinking vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mellum2-1-12b-a2-5b-thinking)
- [Nemotron 3.5 Lightning 30B A3B NVFP4 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-nemotron-3-5-lightning-30b-a3b-nvfp4)
- [Mellum2.1-12B-A2.5B-Thinking vs GPT-6 Astra](/compare/gpt-6-astra-vs-mellum2-1-12b-a2-5b-thinking)
- [Nemotron 3.5 Lightning 30B A3B NVFP4 vs GPT-6 Astra](/compare/gpt-6-astra-vs-nemotron-3-5-lightning-30b-a3b-nvfp4)

## Explore More

- [Mellum2.1-12B-A2.5B-Thinking profile](/models/mellum2-1-12b-a2-5b-thinking)
- [Nemotron 3.5 Lightning 30B A3B NVFP4 profile](/models/nemotron-3-5-lightning-30b-a3b-nvfp4)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)