# GPT-6.1 Sol vs Mellum2.1-12B-A2.5B-Thinking

> Side-by-side benchmark comparison for GPT-6.1 Sol and Mellum2.1-12B-A2.5B-Thinking across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-6-1-sol-vs-mellum2-1-12b-a2-5b-thinking
- Last updated: October 8, 2026

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for GPT-6.1 Sol and Mellum2.1-12B-A2.5B-Thinking.

## Summary

- GPT-6.1 Sol and Mellum2.1-12B-A2.5B-Thinking do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | GPT-6.1 Sol | Mellum2.1-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | OpenAI | JetBrains |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1.05M | 128K |
| Independent public score (not head-to-head) | 81.36 | null |
| Benchmarks Covered | 13 | 7 |
| Pricing (input/output) | $2.00 / $10.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-6.1 Sol public-lane score: 72.4 (Estimated · #6/122)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | GPT-6.1 Sol | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| AutomationBench | 36.1% | Coming soon | Coming soon |
| Terminal-Bench-Science 0.1 | 57.0% | Coming soon | Coming soon |
| ExploitGym | 35.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 17.4% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-6.1 Sol public-lane score: 70.8 (Supported · #8/146)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | GPT-6.1 Sol | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| DeepSWE | 71.9% | Coming soon | Coming soon |
| Bug Hunt Bench | 44.3 fixes | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 82.0% | Coming soon |
| SWE-bench Verified | Coming soon | 47% | Coming soon |
| SWE-bench Pro | Coming soon | 28% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-6.1 Sol public-lane score: 86.8 (#2/28)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | GPT-6.1 Sol | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 96.50% | Coming soon | Coming soon |
| ARC-AGI-2 | 94.2% | Coming soon | Coming soon |
| ARC-AGI-3 | 52.7% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-6.1 Sol public-lane score: 83.9 (Unranked · 1 rankable row)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- GPT-6.1 Sol public-lane score: 82.7 (Supported · #4/174)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | GPT-6.1 Sol | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| HealthBench (raw) | 56.7% | Coming soon | Coming soon |
| HealthBench (length-adjusted) | 58.5% | Coming soon | Coming soon |
| HealthBench Professional | 64.2% | Coming soon | Coming soon |
| HealthBench Professional (raw) | 67.2% | Coming soon | Coming soon |
| HealthBench Hard | 36.2% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 87.8% | Coming soon |
| GPQA-D | Coming soon | 64.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-6.1 Sol public-lane score: Coming soon
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | GPT-6.1 Sol | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 90.6% | Coming soon |

## FAQ

### Can I compare GPT-6.1 Sol and Mellum2.1-12B-A2.5B-Thinking on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [GPT-6.1 Sol vs GPT-6 Astra](/compare/gpt-6-1-sol-vs-gpt-6-astra)
- [Mellum2.1-12B-A2.5B-Thinking vs GPT-6 Astra](/compare/gpt-6-astra-vs-mellum2-1-12b-a2-5b-thinking)
- [GPT-6.1 Sol vs GPT-6 Sol](/compare/gpt-6-1-sol-vs-gpt-6-sol)
- [Mellum2.1-12B-A2.5B-Thinking vs GPT-6 Sol](/compare/gpt-6-sol-vs-mellum2-1-12b-a2-5b-thinking)

## Explore More

- [GPT-6.1 Sol profile](/models/gpt-6-1-sol)
- [Mellum2.1-12B-A2.5B-Thinking profile](/models/mellum2-1-12b-a2-5b-thinking)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)