Model comparison
Hy3 Preview vs Mellum2-12B-A2.5B-Thinking
Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Evidence parity. Hy3 Preview and Mellum2-12B-A2.5B-Thinking share 2 comparable benchmark results. 2 of 8 categories are comparable. 20 results are unique to Hy3 Preview; 3 to Mellum2-12B-A2.5B-Thinking.
Updated July 23, 2026- Shared results
- 2
- Hy3 Preview only
- 20
- Mellum2-12B-A2.5B-Thinking only
- 3
- Comparable categories
- 2 / 8
Treat this as a split decision. Hy3 Preview makes more sense if you need the larger 256K context window; Mellum2-12B-A2.5B-Thinking is the better fit if knowledge is the priority.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 1 evidence category; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Hy3 Preview and Mellum2-12B-A2.5B-Thinking finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
Hy3 Preview gives you the larger context window at 256K, compared with 128K for Mellum2-12B-A2.5B-Thinking.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Hy3 Preview | Δ | Mellum2-12B-A2.5B-Thinking |
|---|---|---|---|
| Knowledge | Hy3 Preview33.8 | Margin→ 23.8 | Mellum2-12B-A2.5B-Thinking57.6 |
| Inst. Following | Hy3 Preview63.1 | Margin→ 13.4 | Mellum2-12B-A2.5B-Thinking76.5 |
| Agentic | Hy3 Preview54.4 | MarginNo overlap | Mellum2-12B-A2.5B-ThinkingNot measured |
| Coding | Hy3 Preview57.8 | MarginNo overlap | Mellum2-12B-A2.5B-ThinkingNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
GPQA
KnowledgeA 87.2%B 57.6%Winner: Hy3 PreviewΔ 29.6GPQA: Hy3 Preview scored 87.2%; Mellum2-12B-A2.5B-Thinking scored 57.6%. Hy3 Preview wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Hy3 Preview | Mellum2-12B-A2.5B-Thinking | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Hy3 Preview$0 input / $0 output | Mellum2-12B-A2.5B-ThinkingNot available | A complete price comparison is not available. |
| Generation speedtokens per second | Hy3 PreviewNot available | Mellum2-12B-A2.5B-ThinkingNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Hy3 PreviewNot available | Mellum2-12B-A2.5B-ThinkingNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Hy3 Preview256K | Mellum2-12B-A2.5B-Thinking128K | Hy3 Preview lists the larger context window. |
Benchmark Deep Dive
Agentic6 benchmarks
Coding5 benchmarks
Reasoning2 benchmarks
KnowledgeMellum2-12B-A2.5B-Thinking wins10 benchmarks
| Benchmark | Hy3 Preview | Mellum2-12B-A2.5B-Thinking | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 41.2% | — | Not comparable |
| GPQASource | 87.2% | 57.6% | Hy3 Preview leads |
| GPQA-DSource | 87.2% | 57.6% | Hy3 Preview leads |
| HLESource | 25.5% | — | Not comparable |
| AA-Omniscience AccuracySource | 31.5% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 73.0% | — | Not comparable |
| AA-GPQA DiamondSource | 89.7% | — | Not comparable |
| AA-HLESource | 31.6% | — | Not comparable |
| AA-Omniscience IndexSource | -18.5% | — | Not comparable |
| MMLU-ReduxSource | — | 86.2% | Not comparable |
Frequently Asked Questions (3)
Which is better, Hy3 Preview or Mellum2-12B-A2.5B-Thinking?
Hy3 Preview and Mellum2-12B-A2.5B-Thinking are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for knowledge tasks, Hy3 Preview or Mellum2-12B-A2.5B-Thinking?
Mellum2-12B-A2.5B-Thinking has the edge for knowledge tasks in this comparison, averaging 57.6 versus 33.8. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Which is better for instruction following, Hy3 Preview or Mellum2-12B-A2.5B-Thinking?
Mellum2-12B-A2.5B-Thinking has the edge for instruction following in this comparison, averaging 76.5 versus 63.1. Hy3 Preview stays close enough that the answer can still flip depending on your workload.
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