# Mellum2.1-12B-A2.5B-Thinking vs Beam 1.0 501B-A23B NVFP4

> Side-by-side benchmark comparison for Mellum2.1-12B-A2.5B-Thinking and Beam 1.0 501B-A23B NVFP4 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mellum2-1-12b-a2-5b-thinking-vs-reflection-beam-nvfp4
- Last updated: October 16, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick Beam 1.0 501B-A23B NVFP4 if you want the stronger benchmark profile. Mellum2.1-12B-A2.5B-Thinking only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Beam 1.0 501B-A23B NVFP4 leads overall 70 to 39.
- The biggest single benchmark swing is Terminal-Bench 2.1 in Agentic, with scores of 17.4% and 78.4%.
- Beam 1.0 501B-A23B NVFP4 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Beam 1.0 501B-A23B NVFP4 also has the larger context window at 1M.

## Model Snapshot

| Property | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 |
|----------|----------|----------|
| Creator | JetBrains | Reflection AI |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 128K | 1M |
| Overall Score | null | null |
| Benchmarks Covered | 7 | 19 |
| Pricing (input/output) | $0.00 / $0.00 | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Not comparable
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Beam 1.0 501B-A23B NVFP4 public-lane score: Coming soon

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 17.4% | 78.4% | Beam 1.0 501B-A23B NVFP4 |
| τ³-bench results | Coming soon | 35.4% | Coming soon |
| HLE w/ tools | Coming soon | 51.1% | Coming soon |
| MCP Atlas | Coming soon | 80.5% | Coming soon |
| BrowseComp | Coming soon | 75.6% | Coming soon |
| DeepSearchQA | Coming soon | 81.1% | Coming soon |

### Coding

- Winner: Not comparable
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Beam 1.0 501B-A23B NVFP4 public-lane score: Coming soon

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 82.0% | Coming soon | Coming soon |
| SWE-bench Verified | 47% | 80.7% | Beam 1.0 501B-A23B NVFP4 |
| SWE-bench Pro | 28% | 65.6% | Beam 1.0 501B-A23B NVFP4 |
| DeepSWE | Coming soon | 42.7% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 78.4% | Coming soon |
| SWE-Atlas Codebase QnA | Coming soon | 31.4% | Coming soon |
| SWE Multilingual | Coming soon | 77.5% | Coming soon |
| SciCode | Coming soon | 46.9% | Coming soon |

### Reasoning

- Winner: Not comparable
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Beam 1.0 501B-A23B NVFP4 public-lane score: 85.5 (Unranked · 3 rankable rows)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 15.4% | Coming soon |
| LongBench v2 | Coming soon | 67.2% | Coming soon |

### Knowledge

- Winner: Not comparable
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Beam 1.0 501B-A23B NVFP4 public-lane score: Coming soon

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | 87.8% | Coming soon | Coming soon |
| GPQA-D | 64.6% | 89.3% | Beam 1.0 501B-A23B NVFP4 |
| HLE w/o tools | Coming soon | 34.8% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Beam 1.0 501B-A23B NVFP4 public-lane score: 86.2 (#44/148)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.6% | Coming soon | Coming soon |
| IFBench | Coming soon | 79.2% | Coming soon |

### Mathematics

- Winner: Not comparable
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Beam 1.0 501B-A23B NVFP4 public-lane score: 87.9 (Unranked · 1 rankable row)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Beam 1.0 501B-A23B NVFP4 | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | Coming soon | 97.5% | Coming soon |

## FAQ

### Which is better overall, Mellum2.1-12B-A2.5B-Thinking or Beam 1.0 501B-A23B NVFP4?

Beam 1.0 501B-A23B NVFP4 is ahead overall on BenchLM right now.

### How many benchmarks does Mellum2.1-12B-A2.5B-Thinking cover on BenchLM?

Mellum2.1-12B-A2.5B-Thinking currently has 7 sourced benchmark scores on BenchLM.

### How many benchmarks does Beam 1.0 501B-A23B NVFP4 cover on BenchLM?

Beam 1.0 501B-A23B NVFP4 currently has 19 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Mellum2.1-12B-A2.5B-Thinking vs Beam 1.0 501B-A23B](/compare/mellum2-1-12b-a2-5b-thinking-vs-reflection-beam)
- [Beam 1.0 501B-A23B NVFP4 vs Beam 1.0 501B-A23B](/compare/reflection-beam-vs-reflection-beam-nvfp4)
- [Mellum2.1-12B-A2.5B-Thinking vs Beam 1.0 501B-A23B FP8](/compare/mellum2-1-12b-a2-5b-thinking-vs-reflection-beam-fp8)
- [Beam 1.0 501B-A23B NVFP4 vs Beam 1.0 501B-A23B FP8](/compare/reflection-beam-fp8-vs-reflection-beam-nvfp4)

## Explore More

- [Mellum2.1-12B-A2.5B-Thinking profile](/models/mellum2-1-12b-a2-5b-thinking)
- [Beam 1.0 501B-A23B NVFP4 profile](/models/reflection-beam-nvfp4)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)