GPT-5.6 Luna vs Nemotron 3 Ultra 550B A55B
Wins 6 of 7 areas
Coding · Agents · Reasoning · Facts · Math · Long documents
Wins 1 of 7 areas
Following instructions
GPT-5.6 Luna is the stronger all-rounder.Nemotron 3 Ultra 550B A55B is better at following instructions.
Scores updated · 35 tests both models report · How we compare
Where each one wins
Tests won in each of the seven areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- CodingWriting and fixing software60GPT-5.6 Luna6 of 6 tests
- ReasoningHard problems that need careful thinking50GPT-5.6 Luna5 of 5 tests
- AgentsCarrying out multi-step tasks on its own40GPT-5.6 Luna4 of 4 tests
- FactsGetting facts right instead of making them up21GPT-5.6 Luna2 of 3 tests
- MathCompetition and research-level math21GPT-5.6 Luna2 of 3 tests
- Long documentsFinding answers in very long texts10GPT-5.6 Luna1 of 1 test
- Following instructionsDoing exactly what it is asked01Nemotron 3 Ultra 550B A55B1 of 1 test
Long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
GPT-5.6 Luna costs 58% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where GPT-5.6 Luna pulls ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+38.9points ahead
- Command-line tasks in a real terminalTerminal-Bench 2.1+27points ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+22.3points ahead
Where Nemotron 3 Ultra 550B A55B pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+62.9points ahead
- Follows detailed instructions exactlyLiveBench · Instruction Following+13.4points ahead
- Fresh competition math problemsLiveBench · Mathematics+1.5points ahead
Every test, side by side
All 35 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGPT-5.6 Luna
- Terminal-Bench 2.1GPT-5.6 Luna by 2780.953.9+27
- SWE-bench VerifiedGPT-5.6 Luna by 22.39370.7+22.3
- SciCodeGPT-5.6 Luna by 13.353.640.3+13.3
- SWE-bench ProGPT-5.6 Luna by 1362.749.7+13
- LiveBench · CodingGPT-5.6 Luna by 12.282.970.7+12.2
- LiveBench · Agentic CodingGPT-5.6 Luna by 9.748.438.7+9.7
AgentsGPT-5.6 Luna
- BrowseCompGPT-5.6 Luna by 38.983.344.4+38.9
- GDPValGPT-5.6 Luna by 22.34825.7+22.3
- τ-Bench V3 · BankingGPT-5.6 Luna by 16.931.114.2+16.9
- Terminal-Bench 4.0GPT-5.6 Luna by 11.111.60.5+11.1
ReasoningGPT-5.6 Luna
- CritPtGPT-5.6 Luna by 17.520.63.1+17.5
- Humanity's Last ExamGPT-5.6 Luna by 11.139.528.4+11.1
- LiveBench · ReasoningGPT-5.6 Luna by 10.985.674.7+10.9
- SimpleBenchGPT-5.6 Luna by 5.146.841.7+5.1
- GPQA DiamondGPT-5.6 Luna by 4.491.186.7+4.4
FactsGPT-5.6 Luna
- AA-Omniscience · Non-hallucinationNemotron 3 Ultra 550B A55B by 62.97.470.3+62.9
- AA-Omniscience · AccuracyGPT-5.6 Luna by 20.142.722.6+20.1
- SimpleQA VerifiedGPT-5.6 Luna by 8.64132.4+8.6
MathGPT-5.6 Luna
- HMMT Feb. 2026GPT-5.6 Luna by 19.798.578.8+19.7
- AIME 2026GPT-5.6 Luna by 3.497.694.2+3.4
- LiveBench · MathematicsNemotron 3 Ultra 550B A55B by 1.587.288.7+1.5
Following instructionsNemotron 3 Ultra 550B A55B
- LiveBench · Instruction FollowingNemotron 3 Ultra 550B A55B by 13.460.173.5+13.4
Other results12 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- GDPval-AA v2GPT-5.6 Luna by 382 rating points15301148+382 rating
- Toolathlon VerifiedGPT-5.6 Luna by 33.667.934.3+33.6
- livebench_data_analysisGPT-5.6 Luna by 23.57854.5+23.5
- Artificial Analysis Coding IndexGPT-5.6 Luna by 22.171.449.3+22.1
- AA Agentic IndexGPT-5.6 Luna by 2142.721.7+21
- BrowseComp (context management)GPT-5.6 Luna by 218463+21
- SWEBench Pro PublicGPT-5.6 Luna by 16.362.746.4+16.3
- AA IntelligenceGPT-5.6 Luna by 14.437.322.9+14.4
- HLE (with tools)GPT-5.6 Luna by 11.548.937.4+11.5
- AA-OmniscienceNemotron 3 Ultra 550B A55B by 9.9-10.3-0.4+9.9
- τ³-Bench BankingGPT-5.6 Luna by 5.924.318.4+5.9
- livebench_languageGPT-5.6 Luna by 1.872.670.8+1.8
Questions people ask
Which is better, GPT-5.6 Luna or Nemotron 3 Ultra 550B A55B?
GPT-5.6 Luna wins six of the seven areas where both have results: coding, agents, reasoning, facts, math and long documents. Nemotron 3 Ultra 550B A55B wins following instructions.
Which is better for coding?
GPT-5.6 Luna. It wins 6 of the 6 coding tests both models report; Nemotron 3 Ultra 550B A55B wins none.
Which is cheaper?
GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens; Nemotron 3 Ultra 550B A55B costs $0.60 and $2.70. That makes GPT-5.6 Luna about 58% cheaper for the same work.
How do you compare the two?
We use the 35 benchmark tests both models have published scores on. The verdict counts the 23 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 12 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.