Model comparison
DeepSeek V4 Flash Base vs Mellum2-12B-A2.5B-Instruct
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Evidence parity. DeepSeek V4 Flash Base and Mellum2-12B-A2.5B-Instruct share 1 comparable benchmark result. 1 of 8 categories are comparable. 23 results are unique to DeepSeek V4 Flash Base; 4 to Mellum2-12B-A2.5B-Instruct.
Updated July 23, 2026- Shared results
- 1
- DeepSeek V4 Flash Base only
- 23
- Mellum2-12B-A2.5B-Instruct only
- 4
- Comparable categories
- 1 / 8
Treat this as a split decision. DeepSeek V4 Flash Base 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 its strengths line up with your actual workload.
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
DeepSeek V4 Flash Base 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 Base 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 Base | Δ | Mellum2-12B-A2.5B-Instruct |
|---|---|---|---|
| Knowledge | DeepSeek V4 Flash Base56.4 | Margin← 15.5 | Mellum2-12B-A2.5B-Instruct40.9 |
| Reasoning | DeepSeek V4 Flash Base44.7 | MarginNo overlap | Mellum2-12B-A2.5B-InstructNot measured |
| Inst. Following | DeepSeek V4 Flash BaseNot measured | MarginNo overlap | Mellum2-12B-A2.5B-Instruct75.8 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | DeepSeek V4 Flash Base | Mellum2-12B-A2.5B-Instruct | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | DeepSeek V4 Flash BaseNot available | Mellum2-12B-A2.5B-InstructNot available | A complete price comparison is not available. |
| Generation speedtokens per second | DeepSeek V4 Flash BaseNot available | Mellum2-12B-A2.5B-InstructNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | DeepSeek V4 Flash BaseNot available | Mellum2-12B-A2.5B-InstructNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | DeepSeek V4 Flash Base1M | Mellum2-12B-A2.5B-Instruct128K | DeepSeek V4 Flash Base lists the larger context window. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | DeepSeek V4 Flash Base | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| BFCL v4Source | — | 44.2% | Not comparable |
Coding2 benchmarks
Reasoning6 benchmarks
KnowledgeDeepSeek V4 Flash Base wins14 benchmarks
| Benchmark | DeepSeek V4 Flash Base | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| AGIEvalSource | 82.6% | — | Not comparable |
| MMLUSource | 88.7% | — | Not comparable |
| MMLU-ReduxSource | 89.4% | 78.1% | DeepSeek V4 Flash Base leads |
| MMLU-ProSource | 68.3% | — | Not comparable |
| MMMLUSource | 88.8% | — | Not comparable |
| C-EvalSource | 92.1% | — | Not comparable |
| CMMLUSource | 90.4% | — | Not comparable |
| MultiLoKoSource | 42.2% | — | Not comparable |
| SimpleQASource | 30.1% | — | Not comparable |
| SuperGPQASource | 46.5% | — | Not comparable |
| FACTS ParametricSource | 33.9% | — | Not comparable |
| TriviaQASource | 82.8% | — | Not comparable |
| GPQASource | — | 40.9% | Not comparable |
| GPQA-DSource | — | 40.9% | Not comparable |
Math3 benchmarks
Multilingual1 benchmarks
| Benchmark | DeepSeek V4 Flash Base | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| MGSMSource | 85.7% | — | Not comparable |
Inst. Following1 benchmarks
| Benchmark | DeepSeek V4 Flash Base | Mellum2-12B-A2.5B-Instruct | Result |
|---|---|---|---|
| IFEvalSource | — | 75.8% | Not comparable |
Frequently Asked Questions (2)
Which is better, DeepSeek V4 Flash Base or Mellum2-12B-A2.5B-Instruct?
DeepSeek V4 Flash Base 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 Base or Mellum2-12B-A2.5B-Instruct?
DeepSeek V4 Flash Base has the edge for knowledge tasks in this comparison, averaging 56.4 versus 40.9. Inside this category, MMLU-Redux is the benchmark that creates the most daylight between them.
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