Model comparison
Mellum2-12B-A2.5B-Instruct vs ZAYA1-8B
Head-to-head evidence from 4 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Evidence parity. Mellum2-12B-A2.5B-Instruct and ZAYA1-8B share 4 comparable benchmark results. 2 of 8 categories are comparable. 1 result is unique to Mellum2-12B-A2.5B-Instruct; 7 to ZAYA1-8B.
Updated July 23, 2026- Shared results
- 4
- Mellum2-12B-A2.5B-Instruct only
- 1
- ZAYA1-8B only
- 7
- Comparable categories
- 2 / 8
Treat this as a split decision. Mellum2-12B-A2.5B-Instruct makes more sense if instruction following is the priority or you would rather avoid the extra latency and token burn of a reasoning model; ZAYA1-8B is the better fit if knowledge is the priority or you need the larger 131K context window.
Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 3 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Mellum2-12B-A2.5B-Instruct and ZAYA1-8B 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.
ZAYA1-8B is the reasoning model in the pair, while Mellum2-12B-A2.5B-Instruct is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. ZAYA1-8B gives you the larger context window at 131K, compared with 128K for Mellum2-12B-A2.5B-Instruct.
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 | Mellum2-12B-A2.5B-Instruct | Δ | ZAYA1-8B |
|---|---|---|---|
| Knowledge | Mellum2-12B-A2.5B-Instruct40.9 | Margin→ 32.7 | ZAYA1-8B73.6 |
| Inst. Following | Mellum2-12B-A2.5B-Instruct75.8 | Margin← 11.7 | ZAYA1-8B64.1 |
| Math | Mellum2-12B-A2.5B-InstructNot measured | MarginNo overlap | ZAYA1-8B80.4 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
GPQA
KnowledgeA 40.9%B 71%Winner: ZAYA1-8BΔ 30.1GPQA: Mellum2-12B-A2.5B-Instruct scored 40.9%; ZAYA1-8B scored 71%. ZAYA1-8B wins this benchmark. - Source ↗
IFEval
Inst. FollowingA 75.8%B 85.6%Winner: ZAYA1-8BΔ 9.8IFEval: Mellum2-12B-A2.5B-Instruct scored 75.8%; ZAYA1-8B scored 85.6%. ZAYA1-8B wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Mellum2-12B-A2.5B-Instruct | ZAYA1-8B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Mellum2-12B-A2.5B-InstructNot available | ZAYA1-8B$0 input / $0 output | A complete price comparison is not available. |
| Generation speedtokens per second | Mellum2-12B-A2.5B-InstructNot available | ZAYA1-8BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Mellum2-12B-A2.5B-InstructNot available | ZAYA1-8BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Mellum2-12B-A2.5B-Instruct128K | ZAYA1-8B131K | ZAYA1-8B lists the larger context window. |
Benchmark Deep Dive
Frequently Asked Questions (3)
Which is better, Mellum2-12B-A2.5B-Instruct or ZAYA1-8B?
Mellum2-12B-A2.5B-Instruct and ZAYA1-8B 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, Mellum2-12B-A2.5B-Instruct or ZAYA1-8B?
ZAYA1-8B has the edge for knowledge tasks in this comparison, averaging 73.6 versus 40.9. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Which is better for instruction following, Mellum2-12B-A2.5B-Instruct or ZAYA1-8B?
Mellum2-12B-A2.5B-Instruct has the edge for instruction following in this comparison, averaging 75.8 versus 64.1. Inside this category, IFEval is the benchmark that creates the most daylight between them.
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