I just remembered that TPU did a powerscaling test:
It seems ADL is very efficient down to around 75W limit or maybe a bit below, but get serious problems at 50W so somewhere between 50 and 75W gamingperformance tanks completely. 5600X at 76W limit is equally efficient as 12900K at 75W.
5800X does not behave the same and scales well at 65W vs stock 142W.
gamingperf at 65W is 98-99% of 142W :O How low you can go on 5800X before performance tanks is a big question, but I'm sure it loses a lot less perf at 45W than 12900K, since it loses over 40% perf at 50W, while I lose 5% at 45W.
The voltage/frequency curve of Ryzen 5k is a bit weird where you get very good linear scaling to around 1.1v.
My 5600X tested at various speeds, lowest voltage/powerusage in CB23:
4.2@0.99v 56W
4.3@1.02v 60W
4.4@1.05v 64W
4.5@1.10v 69W
4.6@1.18v 76W
4.7@1.26v 95W
4.8@1.34v 115W
I think it is quite comparable to 5800X. All these test were done with 4000 ram so I/O-die uses a bit more power than an avg 5600X.
Even though the I/O-die uses a bit of power (10-15W load 3200MHz ram, 20-30W load 4000MHz ram) the mem controller on ADL, I/O etc uses a fair amount of power, but at the same die as cores.
I bet 12600K will have better perf at low tdp due to less cores/cache.