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Model comparison

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

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.

Z.AI
66.06/100
No comparison
2 category wins0 category wins

Public leaderboard positions: GLM-5 #28 (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. GLM-5 and Mellum2-12B-A2.5B-Thinking share 3 comparable benchmark results. 2 of 8 categories are comparable. 46 results are unique to GLM-5; 2 to Mellum2-12B-A2.5B-Thinking.

Updated July 23, 2026
Shared results
3
GLM-5 only
46
Mellum2-12B-A2.5B-Thinking only
2
Comparable categories
2 / 8

Treat this as a split decision. GLM-5 makes more sense if instruction following is the priority or you need the larger 200K context window; Mellum2-12B-A2.5B-Thinking is the better fit if you want the stronger reasoning-first profile.

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

GLM-5 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 GLM-5 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. GLM-5 gives you the larger context window at 200K, 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 GLM-5 and Mellum2-12B-A2.5B-Thinking
CategoryGLM-5ΔMellum2-12B-A2.5B-Thinking
Inst. FollowingGLM-592.6Margin 16.1Mellum2-12B-A2.5B-Thinking76.5
KnowledgeGLM-566.4Margin 8.8Mellum2-12B-A2.5B-Thinking57.6
AgenticGLM-556.2MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
CodingGLM-566.3MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
ReasoningGLM-560.8MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
MathGLM-556.3MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured
MultilingualGLM-583.1MarginNo overlapMellum2-12B-A2.5B-ThinkingNot measured

Decisive benchmark drivers

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

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

    Knowledge
    Source ↗
    A 86%B 57.6%
    Winner: GLM-5Δ 28.4
    GPQA: GLM-5 scored 86%; Mellum2-12B-A2.5B-Thinking scored 57.6%. GLM-5 wins this benchmark.
  2. IFEval

    Inst. Following
    Source ↗
    A 92.6%B 76.5%
    Winner: GLM-5Δ 16.1
    IFEval: GLM-5 scored 92.6%; Mellum2-12B-A2.5B-Thinking scored 76.5%. GLM-5 wins this benchmark.

Operational comparison

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

MetricGLM-5Mellum2-12B-A2.5B-ThinkingComparison
Input / output priceUSD per 1M tokensGLM-5$1 input / $3.2 outputMellum2-12B-A2.5B-ThinkingNot availableA complete price comparison is not available.
Generation speedtokens per secondGLM-574 tok/sMellum2-12B-A2.5B-ThinkingNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGLM-51.64 sMellum2-12B-A2.5B-ThinkingNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensGLM-5200KMellum2-12B-A2.5B-Thinking128KGLM-5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
Terminal-Bench 2.0Source 56.2%Not comparable
Claw-EvalSource 57.7%Not comparable
QwenClawBenchSource 54.1%Not comparable
τ³-bench resultsSource 65.6%Not comparable
DeepPlanningSource 14.6%Not comparable
ToolathlonSource 38%Not comparable
MCP AtlasSource 31.1%Not comparable
MCP-TasksSource 60.8%Not comparable
WideResearchSource 69.8%Not comparable
τ²-bench resultsSource 98.2%Not comparable
CyberGymSource 43.2%Not comparable
APEX-Agents-AASource 14.5%Not comparable
Gert LabsSource 50.99%Not comparable
BFCL v4Source 45.6%Not comparable
Coding
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
SWE-bench VerifiedSource 77.8%Not comparable
SWE-bench Verified*Source 72.8%Not comparable
SWE-bench ProSource 55.1%Not comparable
SWE MultilingualSource 73.3%Not comparable
SWE-RebenchSource 62.8%Not comparable
React Native EvalsSource 74.8%Not comparable
AA-SciCodeSource 46.2%Not comparable
Reasoning
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
LongBench v2Source 60.8%Not comparable
AI-NeedleSource 63.3%Not comparable
AA-LCRSource 63.3%Not comparable
CritPtSource 2.0%Not comparable
KnowledgeGLM-5 wins
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
GPQASource 86%57.6%GLM-5 leads
GPQA-DSource 86.0%57.6%GLM-5 leads
SuperGPQASource 66.8%Not comparable
MMLU-ProSource 85.7%Not comparable
MMLU-Pro (Arcee)Source 85.8%Not comparable
HLESource 50.4%Not comparable
Artificial Analysis Intelligence IndexSource 39.5%Not comparable
AA-GPQA DiamondSource 82.0%Not comparable
AA-HLESource 27.2%Not comparable
AA-Omniscience IndexSource 2.0%Not comparable
AA-Omniscience AccuracySource 26.9%Not comparable
AA-Omniscience Hallucination RateSource 34.0%Not comparable
MMLU-ReduxSource 86.2%Not comparable
Math
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
AIME26Source 95.8%Not comparable
AIME25 (Arcee)Source 93.3%Not comparable
HMMT Feb 2025Source 97.5%Not comparable
HMMT Nov 2025Source 96.9%Not comparable
HMMT Feb 2026Source 86.4%Not comparable
MMAnswerBenchSource 82.5%Not comparable
FrontierMath v2 (Tiers 1-3)Source 16.434%Not comparable
FrontierMath v2 (Tier 4)Source 2.100%Not comparable
Multilingual
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
MMLU-ProXSource 83.1%Not comparable
NOVA-63Source 55.1%Not comparable
Multimodal
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
Design Arena WebsiteSource 1278Not comparable
Inst. FollowingGLM-5 wins
BenchmarkGLM-5Mellum2-12B-A2.5B-ThinkingResult
IFEvalSource 92.6%76.5%GLM-5 leads
AA-IFBenchSource 72.3%Not comparable
Frequently Asked Questions (3)

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

GLM-5 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, GLM-5 or Mellum2-12B-A2.5B-Thinking?

GLM-5 has the edge for knowledge tasks in this comparison, averaging 66.4 versus 57.6. Inside this category, GPQA is the benchmark that creates the most daylight between them.

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

GLM-5 has the edge for instruction following in this comparison, averaging 92.6 versus 76.5. Inside this category, IFEval is the benchmark that creates the most daylight between them.

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Last updated: July 23, 2026

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