* 9900k is boosting to 5ghz which is sacrificing efficiency.
* 9900k PC is delivering a much higher framerate, so it'd also have much higher GPU utilisation.
* Afaik RTX3090 will have high power draw even at low utilisation (large card, lots of memory).
From anandtech:
>Should users be interested, in our testing at 4C/4T and 3.0 GHz, the Core i9-9900K only hit 23W power. Doubling the cores and adding another 50%+ to the frequency causes an almost 7x increase in power consumption.
https://www.anandtech.com/show/13400/intel-9th-gen-core-i9-9...
Look at the 3090s power consumption during media playback: https://www.techpowerup.com/review/zotac-geforce-rtx-3090-tr...