Same standard of work. About 10× the energy.
Claude Haiku 5.5 scores higher than Qwen3.5 397B-A17B on Epoch's Capabilities Index, 158.98 against 146.66, across 58 benchmarks covering coding, agents, long context and writing, while using about 10× less energy per answer. Claude Haiku 5.5 has not faced human head-to-head voting, where Qwen3.5 397B-A17B carries 93,567 votes, worth weighing.
| Claude Haiku 5.5 | Qwen3.5 397B-A17B | |
|---|---|---|
| Energy per answer | 0.515 Wh | 5.17 Wh |
| Carbon released | 0.24 g CO₂ | 2.4 g CO₂ |
| Same carbon as driving | under a metre | 10 metres (31 feet) |
| Energy rank | 98 of 277 | 188 of 277 |
| Capability (58 benchmarks) | 159.0 | 146.7 |
| Human vote rating | - | 1438 |
| Votes cast | - | 93,567 |
| Confidence | Day-one estimate | Calculated |
| Released | 2026-10-07 | 2026-02-13 |
Energy is calculated the same way for every model on this site, from public data and calibrated against laboratory measurement, accurate to roughly a factor of two to three, which is why we only ever state a difference of 5× or more. Capability is Epoch AI's Capabilities Index, one score combining 58 separate benchmarks; the vote rating comes from blind human comparisons. The full method is here.