Skip to main content

Mellum2-12B-A2.5B-Instruct vs o1-pro

Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.

Mellum2-12B-A2.5B-Instruct

27

VS

o1-pro

28

0 categoriesvs1 categories

Pick o1-pro if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Instruct only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

Category Radar

Head-to-Head by Category

Category Breakdown

Knowledge

o1-pro
40.9vs79

+38.1 difference

Operational Comparison

Mellum2-12B-A2.5B-Instruct

o1-pro

Price (per 1M tokens)

N/A

$150 / $600

Speed

N/A

N/A

Latency (TTFT)

N/A

N/A

Context Window

128K

200K

Quick Verdict

Pick o1-pro if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Instruct only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

o1-pro finishes one point ahead on BenchLM's provisional leaderboard, 28 to 27. That is enough to call, but not enough to treat as a blowout. This matchup comes down to a few meaningful edges rather than one model dominating the board.

o1-pro's sharpest advantage is in knowledge, where it averages 79 against 40.9. The single biggest benchmark swing on the page is GPQA, 40.9% to 79%.

o1-pro is the reasoning model in the pair, while Mellum2-12B-A2.5B-Instruct 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. o1-pro gives you the larger context window at 200K, compared with 128K for Mellum2-12B-A2.5B-Instruct.

Benchmark Deep Dive

Frequently Asked Questions (2)

Which is better, Mellum2-12B-A2.5B-Instruct or o1-pro?

o1-pro is ahead on BenchLM's provisional leaderboard, 28 to 27. The biggest single separator in this matchup is GPQA, where the scores are 40.9% and 79%.

Which is better for knowledge tasks, Mellum2-12B-A2.5B-Instruct or o1-pro?

o1-pro has the edge for knowledge tasks in this comparison, averaging 79 versus 40.9. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Related Comparisons

Last updated: June 8, 2026

The AI models change fast. We track them for you.

For engineers, researchers, and the plain curious — a weekly brief on new models, ranking shifts, and pricing changes.

Free. No spam. Unsubscribe anytime.