# GPT-5-Codex vs Nemotron 3 Ultra

> Nemotron 3 Ultra is the stronger model overall, scoring 44.7 to 37.3 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-codex-vs-nemotron-3-ultra
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5-Codex scores higher in 1 category and Nemotron 3 Ultra in 1 category; one gap is clear of the uncertainty.
- The widest gap is in coding, where GPT-5-Codex leads 41.9 to 37.7.
- The biggest single-benchmark swing is WeirdML: 54.5% for GPT-5-Codex and 43.5% for Nemotron 3 Ultra.
- Nemotron 3 Ultra is cheaper at $0.60 / $2.40 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- GPT-5-Codex accepts more context: 400K tokens versus 262K.
- Nemotron 3 Ultra has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| Provider | OpenAI | NVIDIA |
| Noometry Index | 37.3 | 44.7 |
| Rank | 190 | 71 |
| Context | 400K | 262K |
| Input $/M | $1.25 | $0.60 |
| Output $/M | $10 | $2.40 |
| Weights | Proprietary | Open |

## Coding

- GPT-5-Codex: 41.9 (#100)
- Nemotron 3 Ultra: 37.7 (#174)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| WeirdML | 54.5% | 43.5% |
| FrontierCode | — | 13.6% |
| SciCode | — | 40.3% |
| LMArena Coding | — | 1468 |

## Agentic & Tool Use

- GPT-5-Codex: 30.8 (#66)
- Nemotron 3 Ultra: —

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| Terminal-Bench | 44.3% | — |

## Reasoning

- GPT-5-Codex: 30.0 (#80)
- Nemotron 3 Ultra: 30.3 (#78)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | — |
| CritPt | — | 3.1% |
| Chess Puzzles | — | 12% |
| LMArena Hard Prompts | — | 1452 |
| Mystery Game Puzzles | — | 20% |
| DTBench | — | 90.1% |
| LMCA | — | 36.9% |
| Epoch Capabilities Index | — | 146.2 |

## Math

- GPT-5-Codex: —
- Nemotron 3 Ultra: 34.4 (#160)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 86.7% |
| ProofBench | — | 2% |
| LMArena Math | — | 1456 |

## Knowledge

- GPT-5-Codex: —
- Nemotron 3 Ultra: 52.5 (#56)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| GPQA Diamond | — | 85.4% |
| LMArena Expert | — | 1472 |

## Multilingual

- GPT-5-Codex: —
- Nemotron 3 Ultra: 53.7 (#61)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| LMArena Non-English | — | 1427 |
| LMArena Chinese | — | 1498 |
| LMArena French | — | 1475 |
| LMArena German | — | 1471 |
| LMArena Korean | — | 1387 |
| LMArena Russian | — | 1415 |
| LMArena Spanish | — | 1452 |

## Instruction Following

- GPT-5-Codex: —
- Nemotron 3 Ultra: 74.9 (#84)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| LMArena Instruction Following | — | 1417 |

## Long Context

- GPT-5-Codex: —
- Nemotron 3 Ultra: 43.9 (#77)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| LMArena Longer Query | — | 1437 |

## Writing & Preference

- GPT-5-Codex: —
- Nemotron 3 Ultra: 66.3 (#35)

| Benchmark | GPT-5-Codex | Nemotron 3 Ultra |
|---|---|---|
| LMArena Text | — | 1444 |
| LMArena Creative Writing | — | 1392 |
| EQ-Bench Creative Writing | — | 1692 |
| LMArena Multi-Turn | — | 1412 |

## FAQ

### Is GPT-5-Codex better than Nemotron 3 Ultra?

Nemotron 3 Ultra is the stronger model overall, scoring 44.7 to 37.3 on the Noometry Index.

### Which is cheaper, GPT-5-Codex or Nemotron 3 Ultra?

Nemotron 3 Ultra is cheaper. It lists at $0.60 per million input tokens and $2.40 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

### Is GPT-5-Codex or Nemotron 3 Ultra better for coding?

GPT-5-Codex scores higher on coding benchmarks: 41.9 versus 37.7 in the Noometry coding category.

### Which has the bigger context window?

GPT-5-Codex does, with 400K tokens against 262K.

### How many benchmarks do GPT-5-Codex and Nemotron 3 Ultra share?

1 benchmark has published results for both models. GPT-5-Codex has 3 scored results on Noometry and Nemotron 3 Ultra has 29.