As far as I can gather, that's not the case. These guys[0] have been crowdsourcing information about power efficiency for a while now, and the big takeaways right now seem to be that
* Intel is the best for idle (there's several people that have systems that run at less than 5 W for the full system using modified old business minipcs off ebay). Allegedly someone has a 9500T at less than 2 W full system power.
* It doesn't matter which Intel processor you use; all of them for many years will get down to 1 W or less for the CPU at idle. A 14900K will idle just as well as an 8100T, which will be much better than a Ryzen 7950X.
* AMD pretty much never gets below 10 W with any of the Ryzen chiplet CPUs. Only their mobile processors can do it, but they don't sell them retail and they're usually (always?) soldered.
* Every component except the CPU is more important. Your motherboard and PCIe devices need to support power management. You need an efficient PSU (which has nothing to do with the 80-plus rating, which doesn't consider power draw at idle). One bad PCIe device like an SSD or a NIC can draw 10s of watts if it breaks sleep states. Unfortunately, this information seems to be almost entirely undocumented beyond these crowdsourcers.
For a usually idle home-server, Intel seems to be better for power usage, which is unfortunate because AMD tends to have more IO and supports ECC.
* Intel is the best for idle (there's several people that have systems that run at less than 5 W for the full system using modified old business minipcs off ebay). Allegedly someone has a 9500T at less than 2 W full system power.
* It doesn't matter which Intel processor you use; all of them for many years will get down to 1 W or less for the CPU at idle. A 14900K will idle just as well as an 8100T, which will be much better than a Ryzen 7950X.
* AMD pretty much never gets below 10 W with any of the Ryzen chiplet CPUs. Only their mobile processors can do it, but they don't sell them retail and they're usually (always?) soldered.
* Every component except the CPU is more important. Your motherboard and PCIe devices need to support power management. You need an efficient PSU (which has nothing to do with the 80-plus rating, which doesn't consider power draw at idle). One bad PCIe device like an SSD or a NIC can draw 10s of watts if it breaks sleep states. Unfortunately, this information seems to be almost entirely undocumented beyond these crowdsourcers.
For a usually idle home-server, Intel seems to be better for power usage, which is unfortunate because AMD tends to have more IO and supports ECC.
[0] https://www.hardwareluxx.de/community/threads/die-sparsamste...