Model comparison
Mellum2-12B-A2.5B-Instruct vs o3-pro
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Mellum2-12B-A2.5B-Instruct unranked (Not scored); o3-pro #127 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Mellum2-12B-A2.5B-Instruct and o3-pro share 0 comparable benchmark results. 0 of 8 categories are comparable. 5 results are unique to Mellum2-12B-A2.5B-Instruct; 2 to o3-pro.
Updated July 23, 2026- Shared results
- 0
- Mellum2-12B-A2.5B-Instruct only
- 5
- o3-pro only
- 2
- Comparable categories
- 0 / 8
Benchmark data for Mellum2-12B-A2.5B-Instruct and o3-pro is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
o3-pro has the larger context window at 200K, compared with 128K for Mellum2-12B-A2.5B-Instruct.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Mellum2-12B-A2.5B-Instruct | o3-pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Mellum2-12B-A2.5B-InstructNot available | o3-pro$20 input / $80 output | A complete price comparison is not available. |
| Generation speedtokens per second | Mellum2-12B-A2.5B-InstructNot available | o3-pro27 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Mellum2-12B-A2.5B-InstructNot available | o3-pro84.93 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Mellum2-12B-A2.5B-Instruct128K | o3-pro200K | o3-pro lists the larger context window. |
Benchmark Deep Dive
Frequently Asked Questions (3)
Can I compare Mellum2-12B-A2.5B-Instruct and o3-pro on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Mellum2-12B-A2.5B-Instruct and o3-pro today?
o3-pro: $20.00 input / $80.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
Related Comparisons
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.