Model comparison
DeepSeek V4 Flash (High) vs Mellum2-12B-A2.5B-Instruct
Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: DeepSeek V4 Flash (High) #92 (Estimated); Mellum2-12B-A2.5B-Instruct unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. DeepSeek V4 Flash (High) and Mellum2-12B-A2.5B-Instruct share 2 comparable benchmark results. 1 of 8 categories are comparable. 36 results are unique to DeepSeek V4 Flash (High); 3 to Mellum2-12B-A2.5B-Instruct.
Updated July 23, 2026- Shared results
- 2
- DeepSeek V4 Flash (High) only
- 36
- Mellum2-12B-A2.5B-Instruct only
- 3
- Comparable categories
- 1 / 8
Treat this as a split decision. DeepSeek V4 Flash (High) makes more sense if knowledge is the priority or you need the larger 1M context window; Mellum2-12B-A2.5B-Instruct is the better fit if you would rather avoid the extra latency and token burn of a reasoning model.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results 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
DeepSeek V4 Flash (High) and Mellum2-12B-A2.5B-Instruct 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.
DeepSeek V4 Flash (High) 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. DeepSeek V4 Flash (High) gives you the larger context window at 1M, 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 | DeepSeek V4 Flash (High) | Δ | Mellum2-12B-A2.5B-Instruct |
|---|---|---|---|
| Knowledge | DeepSeek V4 Flash (High)52.1 | Margin← 11.2 | Mellum2-12B-A2.5B-Instruct40.9 |
| Agentic | DeepSeek V4 Flash (High)55.3 | MarginNo overlap | Mellum2-12B-A2.5B-InstructNot measured |
| Coding | DeepSeek V4 Flash (High)68.5 | MarginNo overlap | Mellum2-12B-A2.5B-InstructNot measured |
| Math | DeepSeek V4 Flash (High)91.9 | MarginNo overlap | Mellum2-12B-A2.5B-InstructNot measured |
| Inst. Following | DeepSeek V4 Flash (High)Not measured | MarginNo overlap | Mellum2-12B-A2.5B-Instruct75.8 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
GPQA
KnowledgeA 87.4%B 40.9%Winner: DeepSeek V4 Flash (High)Δ 46.5GPQA: DeepSeek V4 Flash (High) scored 87.4%; Mellum2-12B-A2.5B-Instruct scored 40.9%. DeepSeek V4 Flash (High) wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | DeepSeek V4 Flash (High) | Mellum2-12B-A2.5B-Instruct | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | DeepSeek V4 Flash (High)$0.14 input / $0.28 output | Mellum2-12B-A2.5B-InstructNot available | A complete price comparison is not available. |
| Generation speedtokens per second | DeepSeek V4 Flash (High)Not available | Mellum2-12B-A2.5B-InstructNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | DeepSeek V4 Flash (High)Not available | Mellum2-12B-A2.5B-InstructNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | DeepSeek V4 Flash (High)1M | Mellum2-12B-A2.5B-Instruct128K | DeepSeek V4 Flash (High) lists the larger context window. |
Benchmark Deep Dive
Agentic10 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 56.6% | — | Not comparable |
| BrowseCompSource | 53.5% | — | Not comparable |
| HLE w/ toolsSource | 40.3% | — | Not comparable |
| MCP AtlasSource | 67.4% | — | Not comparable |
| ToolathlonSource | 43.5% | — | Not comparable |
| τ²-bench resultsSource | 95.6% | — | Not comparable |
| AA Agentic IndexSource | 28.2% | — | Not comparable |
| GDPval-AASource | 32.4% | — | Not comparable |
| GDPval-AASource | 1147 | — | Not comparable |
| BFCL v4Source | — | 44.2% | Not comparable |
Coding7 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| CodeforcesSource | 2816.0 | — | Not comparable |
| SWE-bench VerifiedSource | 78.6% | — | Not comparable |
| SWE-bench ProSource | 52.3% | — | Not comparable |
| SWE MultilingualSource | 70.2% | — | Not comparable |
| Terminal-Bench 2.0Source | 56.6% | — | Not comparable |
| AA-SciCodeSource | 42.0% | — | Not comparable |
| AA Coding IndexSource | 52.0% | — | Not comparable |
Reasoning4 benchmarks
KnowledgeDeepSeek V4 Flash (High) wins13 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| MMLU-ProSource | 86.4% | — | Not comparable |
| SimpleQASource | 28.9% | — | Not comparable |
| Chinese-SimpleQASource | 73.2% | — | Not comparable |
| GPQASource | 87.4% | 40.9% | DeepSeek V4 Flash (High) leads |
| GPQA-DSource | 87.4% | 40.9% | DeepSeek V4 Flash (High) leads |
| HLESource | 29.4% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 37.5% | — | Not comparable |
| AA-GPQA DiamondSource | 86.7% | — | Not comparable |
| AA-HLESource | 27.8% | — | Not comparable |
| AA-Omniscience IndexSource | -22.3% | — | Not comparable |
| AA-Omniscience AccuracySource | 35.5% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 89.7% | — | Not comparable |
| MMLU-ReduxSource | — | 78.1% | Not comparable |
Math4 benchmarks
Multimodal1 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 1238 | — | Not comparable |
Frequently Asked Questions (2)
Which is better, DeepSeek V4 Flash (High) or Mellum2-12B-A2.5B-Instruct?
DeepSeek V4 Flash (High) and Mellum2-12B-A2.5B-Instruct 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, DeepSeek V4 Flash (High) or Mellum2-12B-A2.5B-Instruct?
DeepSeek V4 Flash (High) has the edge for knowledge tasks in this comparison, averaging 52.1 versus 40.9. Inside this category, GPQA is the benchmark that creates the most daylight between them.
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