Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Mellum2-12B-A2.5B-Thinking
59
o1
57
Pick Mellum2-12B-A2.5B-Thinking if you want the stronger benchmark profile. o1 only becomes the better choice if knowledge is the priority or you need the larger 200K context window.
Knowledge
+18.1 difference
Inst. Following
+15.7 difference
Mellum2-12B-A2.5B-Thinking
o1
N/A
$15 / $60
N/A
98 t/s
N/A
32.29s
128K
200K
Pick Mellum2-12B-A2.5B-Thinking if you want the stronger benchmark profile. o1 only becomes the better choice if knowledge is the priority or you need the larger 200K context window.
Mellum2-12B-A2.5B-Thinking has the cleaner provisional overall profile here, landing at 59 versus 57. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
o1 gives you the larger context window at 200K, compared with 128K for Mellum2-12B-A2.5B-Thinking.
Mellum2-12B-A2.5B-Thinking is ahead on BenchLM's provisional leaderboard, 59 to 57. The biggest single separator in this matchup is GPQA, where the scores are 57.6% and 75.7%.
o1 has the edge for knowledge tasks in this comparison, averaging 75.7 versus 57.6. Inside this category, GPQA is the benchmark that creates the most daylight between them.
o1 has the edge for instruction following in this comparison, averaging 92.2 versus 76.5. Inside this category, IFEval is the benchmark that creates the most daylight between them.
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