GPT-4.5 (OpenAI) and Grok-2 (xAI) are both frontier AI models. GPT-4.5 was published in February 2025 and Grok-2 in August 2024.
GPT-4.5 was trained on 3.8 x 10^26 FLOP, about 12.8x the compute of Grok-2 at 3 x 10^25 FLOP. Training compute is the closest available proxy for how much was invested in a model, though it says nothing on its own about how well that compute was spent.
GPT-4.5 wins the single benchmark both were scored on. Benchmark counts are a crude scoreboard — the evaluations differ wildly in what they measure and in how saturated they are — so the per-benchmark table below matters more than the tally.
| Field | GPT-4.5 | Grok-2 |
|---|---|---|
| Organization | OpenAI | xAI |
| Published | Feb 27, 2025 | Aug 13, 2024 |
| Training compute | 3.8 x 10^26 FLOP | 3 x 10^25 FLOP |
| Training hardware | — | NVIDIA H100 SXM5 80GB |
| Training time | 3K h | — |
| Training cost (2023 USD) | $366M | $32M |
| Accessibility | API access | API access |
| Open weights | No | No |
| Country | United States | United States |
| Benchmark | GPT-4.5 | Grok-2 |
|---|---|---|
| Epoch Capabilities Index(ECI Score) | 137.6 | 130.8 |