The AMD comes ahead in all benchmarks available on that site: https://www.cpu-monkey.com/en/compare_cpu-amd_ryzen_7_7840u-.... I'm not sure where it would fit in terms of perf-per-joule, but there seems to be a very limited amount of benchmarks available (e.g. there seems to be no benchmark for Blender for the AMD, which would be one of the more telling results). The jury is still out for this.