Interesting, maybe this issue only happens for RDNA3?

I’m also using F41 with same kernel but with KDE. Display is 2560x1440 @ 120Hz. On 3D_FULLSCREEN, my pp_dpm_mclk is on 772Mhz most of the time with some occasional 456Mhz, but never drop to 96Mhz. It will only drop to 96Mhz if I change to BOOUP_DEFAULT (or POWER_SAVING).

You can use nvtop or lm_sensors to read the GPU power (PPT)