On a 6900xt GPU best result are achieved using metal benchmark
this GPU ie in DAvinci Resolve beats easily a 3090 FE (windows/Cuda) if the timeline used does not saturate all the 16 Gb available
OpenGL / CL tests are not significant as apple is progressively abandoning that platform
in geekbench my results fluctuate in OpenGL from a value of 100000 to a value of 130000à while for metal from a value of 185000 to a value of 204000
OpenGl:
https://browser.geekbench.com/v5/compute/4185546
Metal:
https://browser.geekbench.com/v5/compute/4185547
in beta 12.3 these values are halved