Model comparison
Mellum2-12B-A2.5B-Thinking vs Muse Spark
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-Thinking unranked (Not scored); Muse Spark #13 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Mellum2-12B-A2.5B-Thinking and Muse Spark share 1 comparable benchmark result. 1 of 8 categories are comparable. 4 results are unique to Mellum2-12B-A2.5B-Thinking; 38 to Muse Spark.
Updated July 23, 2026- Shared results
- 1
- Mellum2-12B-A2.5B-Thinking only
- 4
- Muse Spark only
- 38
- Comparable categories
- 1 / 8
Treat this as a split decision. Mellum2-12B-A2.5B-Thinking makes more sense if knowledge is the priority; Muse Spark is the better fit if you need the larger 262K 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-Thinking and Muse Spark 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.
Muse Spark gives you the larger context window at 262K, 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 | Mellum2-12B-A2.5B-Thinking | Δ | Muse Spark |
|---|---|---|---|
| Knowledge | Mellum2-12B-A2.5B-Thinking57.6 | Margin← 7.2 | Muse Spark50.4 |
| Agentic | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Muse Spark59.0 |
| Coding | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Muse Spark67.8 |
| Reasoning | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Muse Spark42.5 |
| Math | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Muse Spark32.9 |
| Multimodal | Mellum2-12B-A2.5B-ThinkingNot measured | MarginNo overlap | Muse Spark82.5 |
| Inst. Following | Mellum2-12B-A2.5B-Thinking76.5 | MarginNo overlap | Muse SparkNot measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Mellum2-12B-A2.5B-Thinking | Muse Spark | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Mellum2-12B-A2.5B-ThinkingNot available | Muse SparkNot available | A complete price comparison is not available. |
| Generation speedtokens per second | Mellum2-12B-A2.5B-ThinkingNot available | Muse SparkNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Mellum2-12B-A2.5B-ThinkingNot available | Muse SparkNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Mellum2-12B-A2.5B-Thinking128K | Muse Spark262K | Muse Spark lists the larger context window. |
Benchmark Deep Dive
Agentic9 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Muse Spark | Result |
|---|---|---|---|
| BFCL v4Source | 45.6% | — | Not comparable |
| Terminal-Bench 2.0Source | — | 59% | Not comparable |
| τ²-bench resultsSource | — | 91.5% | Not comparable |
| DeepSearchQASource | — | 74.8% | Not comparable |
| CyberGymSource | — | 43.5% | Not comparable |
| Claw-EvalSource | — | 63.8% | Not comparable |
| AA Agentic IndexSource | — | 28.7% | Not comparable |
| GDPval-AASource | — | 32.2% | Not comparable |
| GDPval-AASource | — | 1144 | Not comparable |
Coding6 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Muse Spark | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | — | 77.4% | Not comparable |
| SWE-bench ProSource | — | 52.4% | Not comparable |
| LiveCodeBench ProSource | — | 80.0% | Not comparable |
| Vibe Code BenchSource | — | 19.67% | Not comparable |
| AA Coding IndexSource | — | 58.6% | Not comparable |
| AA-SciCodeSource | — | 51.5% | Not comparable |
Reasoning3 benchmarks
KnowledgeMellum2-12B-A2.5B-Thinking wins13 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Muse Spark | Result |
|---|---|---|---|
| MMLU-ReduxSource | 86.2% | — | Not comparable |
| GPQASource | 57.6% | — | Not comparable |
| GPQA-DSource | 57.6% | 89.5% | Muse Spark leads |
| HLESource | — | 50.4% | Not comparable |
| HLE w/o toolsSource | — | 42.8% | Not comparable |
| HealthBench HardSource | — | 42.8% | Not comparable |
| MedXpertQA (Text)Source | — | 52.6% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 43.1% | Not comparable |
| AA-GPQA DiamondSource | — | 88.4% | Not comparable |
| AA-HLESource | — | 39.9% | Not comparable |
| AA-Omniscience IndexSource | — | 4.1% | Not comparable |
| AA-Omniscience AccuracySource | — | 44.6% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 73.2% | Not comparable |
Math2 benchmarks
Multimodal8 benchmarks
| Benchmark | Mellum2-12B-A2.5B-Thinking | Muse Spark | Result |
|---|---|---|---|
| CharXivSource | — | 86.4% | Not comparable |
| MMMU-ProSource | — | 80.4% | Not comparable |
| ERQASource | — | 64.7% | Not comparable |
| SimpleVQASource | — | 71.3% | Not comparable |
| ScreenSpot ProSource | — | 84.1% | Not comparable |
| ZeroBenchSource | — | 33.0% | Not comparable |
| MedXpertQA (MM)Source | — | 78.4% | Not comparable |
| AA-MMMU-ProSource | — | 80.5% | Not comparable |
Frequently Asked Questions (2)
Which is better, Mellum2-12B-A2.5B-Thinking or Muse Spark?
Mellum2-12B-A2.5B-Thinking and Muse Spark 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-Thinking or Muse Spark?
Mellum2-12B-A2.5B-Thinking has the edge for knowledge tasks in this comparison, averaging 57.6 versus 50.4. Inside this category, GPQA-D is the benchmark that creates the most daylight between them.
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