The thesis I'll try to state again more clearly is that bigger parts at lower frequencies can trump smaller parts at higher frequencies. Efficiencies increase

The thesis I'll try to state again more clearly is that bigger parts at lower frequencies can trump smaller parts at higher frequencies. Efficiencies increase significantly as you downclock. Sure, a mobile part runs 15w. But it's relatively inefficient at doing so. If you want to drop it to 7w, now you're pretty efficient (Steam Deck lets you TDP down 15 -> 3w!!). But you are too slow for most games. Starting with a big APU with gobs of ram bandwidth and downclocking that system is going to get you much better results from that 15w than using the small part at 15w.