# Atria Dawn Preview vs Mellum2-12B-A2.5B-Thinking

> Side-by-side benchmark comparison for Atria Dawn Preview and Mellum2-12B-A2.5B-Thinking across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/atria-dawn-preview-vs-mellum2-12b-a2-5b-thinking
- Last updated: September 14, 2026

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

## Quick Verdict

Evidence is too thin for a benchmark verdict: Atria Dawn Preview and Mellum2-12B-A2.5B-Thinking 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.
- Atria Dawn Preview has the larger published context window at 256K.

## Model Snapshot

| Property | Atria Dawn Preview | Mellum2-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | Shanghai Artificial Intelligence Laboratory | JetBrains |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | 128K |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 13 | 6 |
| Pricing (input/output) | $0.00 / $0.00 | N/A |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Atria Dawn Preview public-lane score: 57.9 (Estimated · #31/153)
- Mellum2-12B-A2.5B-Thinking public-lane score: 46 (Estimated · #80/153)

| Benchmark | Atria Dawn Preview | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| AutomationBench | 53.8% | Coming soon | Coming soon |
| BFCL v4 | 77.0% | 45.6% | Atria Dawn Preview |
| CyberGym | 86.5% | Coming soon | Coming soon |
| DeepSearchQA | 96.0% | Coming soon | Coming soon |
| BrowseComp | 92.5% | Coming soon | Coming soon |
| skillsBench | 66.4% | Coming soon | Coming soon |
| MLE-Bench Lite | 86.2% | Coming soon | Coming soon |
| WideResearch | 81.9% | Coming soon | Coming soon |
| τ³-bench results | 41.2% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 78.3% | Coming soon | Coming soon |
| JobBench | 50.3% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Atria Dawn Preview public-lane score: 51.6 (Estimated · #51/152)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Atria Dawn Preview | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 78.3% | Coming soon | Coming soon |
| SWE-bench Pro | 59.6% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 69.9% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Atria Dawn Preview public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: 46.5 (Estimated · #103/183)

| Benchmark | Atria Dawn Preview | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | Coming soon | 86.2% | Coming soon |
| GPQA | Coming soon | 57.6% | Coming soon |
| GPQA-D | Coming soon | 57.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Atria Dawn Preview public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Atria Dawn Preview | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 76.5% | Coming soon |

## FAQ

### Is there enough evidence to pick between Atria Dawn Preview and Mellum2-12B-A2.5B-Thinking?

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

- [Atria Dawn Preview vs Mellum2-12B-A2.5B-Instruct](/compare/atria-dawn-preview-vs-mellum2-12b-a2-5b-instruct)
- [Mellum2-12B-A2.5B-Thinking vs Mellum2-12B-A2.5B-Instruct](/compare/mellum2-12b-a2-5b-instruct-vs-mellum2-12b-a2-5b-thinking)
- [Atria Dawn Preview vs Claude Fable 5.1](/compare/atria-dawn-preview-vs-claude-fable-5-1)
- [Mellum2-12B-A2.5B-Thinking vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mellum2-12b-a2-5b-thinking)

## Explore More

- [Atria Dawn Preview profile](/models/atria-dawn-preview)
- [Mellum2-12B-A2.5B-Thinking profile](/models/mellum2-12b-a2-5b-thinking)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)