Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Sonnet 5
94
Mellum2-12B-A2.5B-Thinking
58
Pick Claude Sonnet 5 if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Thinking only becomes the better choice if coding is the priority.
Coding
+6.7 difference
Knowledge
+0.2 difference
Claude Sonnet 5
Mellum2-12B-A2.5B-Thinking
$3 / $15
N/A
N/A
N/A
N/A
N/A
1M
128K
Pick Claude Sonnet 5 if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Thinking only becomes the better choice if coding is the priority.
Claude Sonnet 5 is clearly ahead on the provisional aggregate, 94 to 58. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 5 gives you the larger context window at 1M, compared with 128K for Mellum2-12B-A2.5B-Thinking.
Claude Sonnet 5 is ahead on BenchLM's provisional leaderboard, 94 to 58.
Mellum2-12B-A2.5B-Thinking has the edge for knowledge tasks in this comparison, averaging 57.6 versus 57.4. Claude Sonnet 5 stays close enough that the answer can still flip depending on your workload.
Mellum2-12B-A2.5B-Thinking has the edge for coding in this comparison, averaging 69.9 versus 63.2. Claude Sonnet 5 stays close enough that the answer can still flip depending on your workload.
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