Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-4.1 nano
26
Mellum2-12B-A2.5B-Thinking
59
Pick Mellum2-12B-A2.5B-Thinking if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if instruction following is the priority or you need the larger 1M context window.
Knowledge
+7.3 difference
Inst. Following
+6.7 difference
GPT-4.1 nano
Mellum2-12B-A2.5B-Thinking
$0.1 / $0.4
N/A
181 t/s
N/A
0.63s
N/A
1M
128K
Pick Mellum2-12B-A2.5B-Thinking if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if instruction following is the priority or you need the larger 1M context window.
Mellum2-12B-A2.5B-Thinking is clearly ahead on the provisional aggregate, 59 to 26. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Mellum2-12B-A2.5B-Thinking's sharpest advantage is in knowledge, where it averages 57.6 against 50.3. The single biggest benchmark swing on the page is GPQA, 50.3% to 57.6%. GPT-4.1 nano does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.
Mellum2-12B-A2.5B-Thinking is the reasoning model in the pair, while GPT-4.1 nano 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. GPT-4.1 nano gives you the larger context window at 1M, compared with 128K for Mellum2-12B-A2.5B-Thinking.
Mellum2-12B-A2.5B-Thinking is ahead on BenchLM's provisional leaderboard, 59 to 26. The biggest single separator in this matchup is GPQA, where the scores are 50.3% and 57.6%.
Mellum2-12B-A2.5B-Thinking has the edge for knowledge tasks in this comparison, averaging 57.6 versus 50.3. Inside this category, GPQA is the benchmark that creates the most daylight between them.
GPT-4.1 nano has the edge for instruction following in this comparison, averaging 83.2 versus 76.5. Inside this category, IFEval is the benchmark that creates the most daylight between them.
For engineers, researchers, and the plain curious — a weekly brief on new models, ranking shifts, and pricing changes.
Free. No spam. Unsubscribe anytime.