Model comparison
Mellum2-12B-A2.5B-Instruct vs MiMo-V2-Flash
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Mellum2-12B-A2.5B-Instruct unranked (Not scored); MiMo-V2-Flash #91 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Mellum2-12B-A2.5B-Instruct and MiMo-V2-Flash share 1 comparable benchmark result. 1 of 8 categories are comparable. 4 results are unique to Mellum2-12B-A2.5B-Instruct; 18 to MiMo-V2-Flash.
Updated July 23, 2026- Shared results
- 1
- Mellum2-12B-A2.5B-Instruct only
- 4
- MiMo-V2-Flash only
- 18
- Comparable categories
- 1 / 8
Treat this as a split decision. Mellum2-12B-A2.5B-Instruct makes more sense if you would rather avoid the extra latency and token burn of a reasoning model; MiMo-V2-Flash is the better fit if knowledge is the priority or you need the larger 256K context window.
Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 1 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 MiMo-V2-Flash 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.
MiMo-V2-Flash 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. MiMo-V2-Flash gives you the larger context window at 256K, 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 | MiMo-V2-Flash |
|---|---|---|---|
| Knowledge | Mellum2-12B-A2.5B-Instruct40.9 | Margin→ 43.8 | MiMo-V2-Flash84.7 |
| Coding | Mellum2-12B-A2.5B-InstructNot measured | MarginNo overlap | MiMo-V2-Flash73.4 |
| Inst. Following | Mellum2-12B-A2.5B-Instruct75.8 | MarginNo overlap | MiMo-V2-FlashNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
GPQA
KnowledgeA 40.9%B 83.7%Winner: MiMo-V2-FlashΔ 42.8GPQA: Mellum2-12B-A2.5B-Instruct scored 40.9%; MiMo-V2-Flash scored 83.7%. MiMo-V2-Flash 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 | MiMo-V2-Flash | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Mellum2-12B-A2.5B-InstructNot available | MiMo-V2-Flash$0 input / $0 output | A complete price comparison is not available. |
| Generation speedtokens per second | Mellum2-12B-A2.5B-InstructNot available | MiMo-V2-Flash129 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Mellum2-12B-A2.5B-InstructNot available | MiMo-V2-Flash2.14 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Mellum2-12B-A2.5B-Instruct128K | MiMo-V2-Flash256K | MiMo-V2-Flash lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding3 benchmarks
Reasoning2 benchmarks
KnowledgeMiMo-V2-Flash wins10 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Instruct | MiMo-V2-Flash | Result |
|---|---|---|---|
| MMLU-ReduxSource | 78.1% | — | Not comparable |
| GPQASource | 40.9% | 83.7% | MiMo-V2-Flash leads |
| GPQA-DSource | 40.9% | — | Not comparable |
| MMLU-ProSource | — | 84.9% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 24.7% | Not comparable |
| AA-GPQA DiamondSource | — | 65.6% | Not comparable |
| AA-HLESource | — | 8.0% | Not comparable |
| AA-Omniscience IndexSource | — | -48.5% | Not comparable |
| AA-Omniscience AccuracySource | — | 15.2% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 75.1% | Not comparable |
Math1 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Instruct | MiMo-V2-Flash | Result |
|---|---|---|---|
| AIME 2025Source | — | 94.1% | Not comparable |
Frequently Asked Questions (2)
Which is better, Mellum2-12B-A2.5B-Instruct or MiMo-V2-Flash?
Mellum2-12B-A2.5B-Instruct and MiMo-V2-Flash 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 MiMo-V2-Flash?
MiMo-V2-Flash has the edge for knowledge tasks in this comparison, averaging 84.7 versus 40.9. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Related Comparisons
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.