GPT-5.2-Codex scores 26.4 on the Respan Index (#74), ahead of NVIDIA Nemotron 3 Ultra 550B-A55B NVFP4 at 26.0 (#75). GPT-5.2-Codex leads on 6 of the 7 benchmarks both report. NVIDIA Nemotron 3 Ultra 550B-A55B NVFP4 has the larger context window (1M tokens).
* Estimated: no published scores in that category. How the Respan Index works
| LiveBench Language (LiveBench) | 73.7% | 70.8% |
| LiveBench Mathematics (LiveBench) | 88.8% | 88.7% |
| LiveBench Reasoning (LiveBench) | 77.7% | 74.7% |
Higher is better. Each score links to where it was published.