# DeepSeek V3 vs Mellum2-12B-A2.5B-Thinking

> Side-by-side benchmark comparison for DeepSeek V3 and Mellum2-12B-A2.5B-Thinking across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/deepseek-v3-vs-mellum2-12b-a2-5b-thinking
- Last updated: September 4, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: DeepSeek V3 and Mellum2-12B-A2.5B-Thinking share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.

## Model Snapshot

| Property | DeepSeek V3 | Mellum2-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | DeepSeek | JetBrains |
| Type | Open Weight | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 128K | 128K |
| Independent public score (not head-to-head) | 43.74 | null |
| Benchmarks Covered | 6 | 6 |
| Pricing (input/output) | $0.27 / $1.10 | N/A |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- DeepSeek V3 public-lane score: 38.5 (Estimated · #124/151)
- Mellum2-12B-A2.5B-Thinking public-lane score: 48.3 (Estimated · #76/151)

| Benchmark | DeepSeek V3 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| BFCL v4 | Coming soon | 45.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- DeepSeek V3 public-lane score: 41.1 (Estimated · #135/183)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | DeepSeek V3 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench | 37.6% | Coming soon | Coming soon |
| SWE-bench Verified | 42% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 69.9% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- DeepSeek V3 public-lane score: 43.8 (Unranked · 2 rankable rows)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- DeepSeek V3 public-lane score: 40.7 (Estimated · #136/181)
- Mellum2-12B-A2.5B-Thinking public-lane score: 48.8 (Estimated · #96/181)

| Benchmark | DeepSeek V3 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 59.1% | 57.6% | DeepSeek V3 |
| MMLU-Pro | 75.9% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 86.2% | Coming soon |
| GPQA-D | Coming soon | 57.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- DeepSeek V3 public-lane score: 39.6 (#102/120)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | DeepSeek V3 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 86.1% | 76.5% | DeepSeek V3 |

### Mathematics

- Winner: Insufficient shared evidence
- DeepSeek V3 public-lane score: 26.2 (Unranked · 1 rankable row)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | DeepSeek V3 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 1.724% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between DeepSeek V3 and Mellum2-12B-A2.5B-Thinking?

Not yet. The models share only 2 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

- [DeepSeek V3 vs Mellum2-12B-A2.5B-Instruct](/compare/deepseek-v3-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)
- [DeepSeek V3 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-deepseek-v3)
- [Mellum2-12B-A2.5B-Thinking vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mellum2-12b-a2-5b-thinking)

## Explore More

- [DeepSeek V3 profile](/models/deepseek-v3)
- [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)