A benchmark comparison shared by Chinese YouTuber Geekerwan and discussed widely across Reddit suggests that AMD's Ryzen 9 9955HX3D outpaces Intel's Core Ultra 9 285HX in multi-core performance per watt, based on Cinebench R23 results.https://www.notebookcheck.net/Chinese-YouTuber-s-benchmarks-show-AMD-Ryzen-9-9955HX3D-offering-better-multi-core-efficiency-than-Intel-Core-Ultra-9-285HX.1026286.0.html
This curve is unique and different from others I've seen.
In relation to other power x performance curves with 275hx vs 9955hx it is displaced with AMD above and, mainly, Intel below.
The 275hx leads until about 90W, where the 9955hx matches and surpasses it by a small margin until about 140W, where Intel retakes the lead.