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Model comparison

Mellum2-12B-A2.5B-Instruct vs Qwen3.5 397B

Data verified

Head-to-head evidence from 3 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

N/A
No comparison
57.01/100
0 category wins2 category wins

Public leaderboard positions: Mellum2-12B-A2.5B-Instruct unranked (Not scored); Qwen3.5 397B #71 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Mellum2-12B-A2.5B-Instruct and Qwen3.5 397B share 3 comparable benchmark results. 2 of 8 categories are comparable. 2 results are unique to Mellum2-12B-A2.5B-Instruct; 52 to Qwen3.5 397B.

Updated July 23, 2026
Shared results
3
Mellum2-12B-A2.5B-Instruct only
2
Qwen3.5 397B only
52
Comparable categories
2 / 8

Treat this as a split decision. Mellum2-12B-A2.5B-Instruct makes more sense if its workflow fits your team better; Qwen3.5 397B is the better fit if instruction following is the priority.

Confidence note. This is a partial-evidence comparison with 3 shared benchmark results across 2 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 Qwen3.5 397B 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.

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 scores and score margins for Mellum2-12B-A2.5B-Instruct and Qwen3.5 397B
CategoryMellum2-12B-A2.5B-InstructΔQwen3.5 397B
Inst. FollowingMellum2-12B-A2.5B-Instruct75.8Margin→ 16.8Qwen3.5 397B92.6
KnowledgeMellum2-12B-A2.5B-Instruct40.9Margin→ 15.7Qwen3.5 397B56.6
AgenticMellum2-12B-A2.5B-InstructNot measuredMarginNo overlapQwen3.5 397B56.5
CodingMellum2-12B-A2.5B-InstructNot measuredMarginNo overlapQwen3.5 397B66.5
ReasoningMellum2-12B-A2.5B-InstructNot measuredMarginNo overlapQwen3.5 397B63.2
MathMellum2-12B-A2.5B-InstructNot measuredMarginNo overlapQwen3.5 397B90.6
MultilingualMellum2-12B-A2.5B-InstructNot measuredMarginNo overlapQwen3.5 397B84.7
MultimodalMellum2-12B-A2.5B-InstructNot measuredMarginNo overlapQwen3.5 397B79.6

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Mellum2-12B-A2.5B-InstructB · Qwen3.5 397B

  1. GPQA

    Knowledge
    Source ↗
    A 40.9%B 88.4%
    Winner: Qwen3.5 397BΔ 47.5
    GPQA: Mellum2-12B-A2.5B-Instruct scored 40.9%; Qwen3.5 397B scored 88.4%. Qwen3.5 397B wins this benchmark.

  2. IFEval

    Inst. Following
    Source ↗
    A 75.8%B 92.6%
    Winner: Qwen3.5 397BΔ 16.8
    IFEval: Mellum2-12B-A2.5B-Instruct scored 75.8%; Qwen3.5 397B scored 92.6%. Qwen3.5 397B wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricMellum2-12B-A2.5B-InstructQwen3.5 397BComparison
Input / output priceUSD per 1M tokensMellum2-12B-A2.5B-InstructNot availableQwen3.5 397B$0.6 input / $3.6 outputA complete price comparison is not available.
Generation speedtokens per secondMellum2-12B-A2.5B-InstructNot availableQwen3.5 397B96 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenMellum2-12B-A2.5B-InstructNot availableQwen3.5 397B2.44 sA complete latency comparison is not available.
Context windowmaximum listed tokensMellum2-12B-A2.5B-Instruct128KQwen3.5 397B128KListed context windows are equal.

Benchmark Deep Dive

Agentic
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
BFCL v4Source 44.2%—Not comparable
Terminal-Bench 2.0Source —52.5%Not comparable
BrowseCompSource —62%Not comparable
Claw-EvalSource —56.8%Not comparable
QwenClawBenchSource —51.8%Not comparable
τ³-bench resultsSource —68.4%Not comparable
VITA-BenchSource —43.7%Not comparable
DeepPlanningSource —37.6%Not comparable
ToolathlonSource —36.3%Not comparable
MCP AtlasSource —46.1%Not comparable
MCP-TasksSource —74.2%Not comparable
WideResearchSource —74.0%Not comparable
τ²-bench resultsSource —95.6%Not comparable
Gert LabsSource —46.76%Not comparable
ResearchClawBenchSource —14.2%Not comparable
AA Agentic IndexSource —19.9%Not comparable
APEX-Agents-AASource —15.3%Not comparable
GDPval-AASource —23.1%Not comparable
GDPval-AASource —962Not comparable
Coding
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
SWE-bench VerifiedSource —76.2%Not comparable
LiveCodeBench v6Source —83.6%Not comparable
SWE-bench ProSource —50.9%Not comparable
AA-SciCodeSource —42.0%Not comparable
AA Coding IndexSource —48.2%Not comparable
Reasoning
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
LongBench v2Source —63.2%Not comparable
AI-NeedleSource —68.7%Not comparable
AA-LCRSource —65.7%Not comparable
CritPtSource —1.7%Not comparable
KnowledgeQwen3.5 397B wins
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
MMLU-ReduxSource 78.1%94.9%Qwen3.5 397B leads
GPQASource 40.9%88.4%Qwen3.5 397B leads
GPQA-DSource 40.9%—Not comparable
SuperGPQASource —70.4%Not comparable
MMLU-ProSource —87.8%Not comparable
C-EvalSource —93%Not comparable
HLESource —28.7%Not comparable
Artificial Analysis Intelligence IndexSource —33.7%Not comparable
AA-GPQA DiamondSource —89.3%Not comparable
AA-HLESource —27.3%Not comparable
AA-Omniscience IndexSource —-29.8%Not comparable
AA-Omniscience AccuracySource —31.4%Not comparable
AA-Omniscience Hallucination RateSource —89.1%Not comparable
Math
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
AIME26Source —93.3%Not comparable
HMMT Feb 2025Source —94.8%Not comparable
HMMT Nov 2025Source —92.7%Not comparable
HMMT Feb 2026Source —87.9%Not comparable
MMAnswerBenchSource —80.9%Not comparable
Multilingual
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
MMLU-ProXSource —84.7%Not comparable
NOVA-63Source —59.1%Not comparable
Multimodal
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
MMMU-ProSource —79%Not comparable
MathVisionSource —88.6%Not comparable
CharXivSource —80.8%Not comparable
VideoMMMUSource —84.7%Not comparable
ScreenSpot ProSource —65.6%Not comparable
V*Source —95.8%Not comparable
AA-MMMU-ProSource —77.3%Not comparable
Inst. FollowingQwen3.5 397B wins
BenchmarkMellum2-12B-A2.5B-InstructQwen3.5 397BResult
IFEvalSource 75.8%92.6%Qwen3.5 397B leads
AA-IFBenchSource —78.8%Not comparable
Frequently Asked Questions (3)

Which is better, Mellum2-12B-A2.5B-Instruct or Qwen3.5 397B?

Mellum2-12B-A2.5B-Instruct and Qwen3.5 397B 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 Qwen3.5 397B?

Qwen3.5 397B has the edge for knowledge tasks in this comparison, averaging 56.6 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 Qwen3.5 397B?

Qwen3.5 397B has the edge for instruction following in this comparison, averaging 92.6 versus 75.8. Inside this category, IFEval is the benchmark that creates the most daylight between them.

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