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Model comparison

Inkling vs Mellum2-12B-A2.5B-Thinking

Data verified

Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.

Thinking Machines Lab
67.54/100
No comparison
1 category wins1 category wins

Public leaderboard positions: Inkling #20 (Supported); Mellum2-12B-A2.5B-Thinking unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Inkling and Mellum2-12B-A2.5B-Thinking share 2 comparable benchmark results. 2 of 8 categories are comparable. 30 results are unique to Inkling; 3 to Mellum2-12B-A2.5B-Thinking.

Updated July 23, 2026
Shared results
2
Inkling only
30
Mellum2-12B-A2.5B-Thinking only
3
Comparable categories
2 / 8

Treat this as a split decision. Inkling makes more sense if instruction following is the priority or you need the larger 1M context window; Mellum2-12B-A2.5B-Thinking is the better fit if knowledge is the priority or you want the stronger reasoning-first profile.

Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 1 evidence category; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Inkling and Mellum2-12B-A2.5B-Thinking 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.

Mellum2-12B-A2.5B-Thinking is the reasoning model in the pair, while Inkling 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. Inkling gives you the larger context window at 1M, 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 scores and score margins for Inkling and Mellum2-12B-A2.5B-Thinking
CategoryInklingΔMellum2-12B-A2.5B-Thinking
KnowledgeInkling51.6Margin 6.0Mellum2-12B-A2.5B-Thinking57.6
Inst. FollowingInkling79.8Margin 3.3Mellum2-12B-A2.5B-Thinking76.5
AgenticInkling69.4MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
CodingInkling68.6MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
MathInkling97.1MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
MultimodalInkling76.5MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured

Decisive benchmark drivers

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

More
A · InklingB · Mellum2-12B-A2.5B-Thinking
  1. GPQA

    Knowledge
    Source ↗
    A 87.9%B 57.6%
    Winner: InklingΔ 30.3
    GPQA: Inkling scored 87.9%; Mellum2-12B-A2.5B-Thinking scored 57.6%. Inkling wins this benchmark.

Operational comparison

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

MetricInklingMellum2-12B-A2.5B-ThinkingComparison
Input / output priceUSD per 1M tokensInkling$1.87 input / $4.68 outputMellum2-12B-A2.5B-ThinkingNot availableA complete price comparison is not available.
Generation speedtokens per secondInklingNot availableMellum2-12B-A2.5B-ThinkingNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenInklingNot availableMellum2-12B-A2.5B-ThinkingNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensInkling1MMellum2-12B-A2.5B-Thinking128KInkling lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
Terminal-Bench 2.0Source 63.8%Not comparable
BrowseCompSource 77.1%Not comparable
MCP AtlasSource 74.1%Not comparable
Design Arena Agentic Web DevSource 1257Not comparable
AA Agentic IndexSource 32.3%Not comparable
GDPval-AASource 36.9%Not comparable
GDPval-AASource 1239Not comparable
AA BriefcaseSource 836Not comparable
AA Tau3 BankingSource 23.7%Not comparable
BFCL v4Source 45.6%Not comparable
Coding
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
SWE-bench VerifiedSource 77.6%Not comparable
SWE-bench ProSource 54.3%Not comparable
Terminal-Bench 2.0Source 63.8%Not comparable
AA Coding IndexSource 52.1%Not comparable
AA-SciCodeSource 46.1%Not comparable
Reasoning
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
AA-LCRSource 63.3%Not comparable
CritPtSource 5.4%Not comparable
KnowledgeMellum2-12B-A2.5B-Thinking wins
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
GPQASource 87.9%57.6%Inkling leads
GPQA-DSource 87.9%57.6%Inkling leads
HLESource 46%Not comparable
HLE w/o toolsSource 30%Not comparable
Artificial Analysis Intelligence IndexSource 40.7%Not comparable
AA-GPQA DiamondSource 87.2%Not comparable
AA-HLESource 29.7%Not comparable
AA-Omniscience IndexSource 2.1%Not comparable
AA-Omniscience AccuracySource 40.0%Not comparable
AA-Omniscience Hallucination RateSource 63.1%Not comparable
MMLU-ReduxSource 86.2%Not comparable
Math
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
AIME26Source 97.1%Not comparable
Multimodal
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
MMMU-ProSource 73.5%Not comparable
CharXivSource 82%Not comparable
CharXiv w/o toolsSource 78.1%Not comparable
AA-MMMU-ProSource 73.5%Not comparable
Inst. FollowingInkling wins
BenchmarkInklingMellum2-12B-A2.5B-ThinkingResult
IFBenchSource 79.8%Not comparable
IFEvalSource 76.5%Not comparable
Frequently Asked Questions (3)

Which is better, Inkling or Mellum2-12B-A2.5B-Thinking?

Inkling and Mellum2-12B-A2.5B-Thinking 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, Inkling or Mellum2-12B-A2.5B-Thinking?

Mellum2-12B-A2.5B-Thinking has the edge for knowledge tasks in this comparison, averaging 57.6 versus 51.6. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for instruction following, Inkling or Mellum2-12B-A2.5B-Thinking?

Inkling has the edge for instruction following in this comparison, averaging 79.8 versus 76.5. Mellum2-12B-A2.5B-Thinking stays close enough that the answer can still flip depending on your workload.

Related Comparisons

Last updated: July 23, 2026

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