Raspberry Pis may be "green" in that they are cheap, but power efficient they aren't. They have barely any power management support, making their idle power usage higher than even some x86 chips.
It's not hard for x86 laptops to idle below 4W (see Surface https://www.notebookcheck.net/Microsoft-Surface-Go-Pentium-6... , even Pro ones with screen on they idle well below 10W). With 10W just for the SoC you get into desktop or gaming laptop territory.
I have a full x86 system that idles at 1.7W _at the wall_ https://news.ycombinator.com/item?id=26639929 . This is an off-the-shelf ASUS PN40 mini-desktop, running an N4000, and includes 8GB RAM, a SATA SSD, and Gigabit ethernet, all running and accepting requests.
> I have a full x86 system that idles at 1.7W _at the wall_
A single stick of DDR1/2/3 ram uses more than that alone.
SATA SSDs are typically 0.5-1W idling.
The mobo chipset, figure at least a few watts
That doesn't even account for CPU idle power consumption.
Whatever you're using for power monitoring isn't accurate. Probably doesn't fully integrate, instead using sampling, and the sampling rate isn't high enough to show true power consumption from your PC's switching PSU.
It's DDR3L, not DDR3. Even the active power use of the stick is not going to be > 0.5W. And RAPL/ACPI can show the CPU/chipset (respectively) consumption, and it averages less than 1W. The official ASUS measurement is at ~3.7W https://csr.asus.com/english/file/ErP_PN40.pdf , and that is with Windows, 8 GB stick and 2 SSDs (personally I couldn't get it to idle at less than 6-7W with Windows).
Again: there are laptops that idle at these values, and this is even worse than a CPU laptop -- it's an Atom. Think S0i3... which keeps the RAM (in SR), chipset, and a shitton of things awake and yet consumes way less than 1W.
> Whatever you're using for power monitoring isn't accurate.
Sure (as in: one can never disagree with that), but the point is: it's still at least half the consumption of the Raspberry Pi 4, and lower than the consumption of a Raspberry Pi 3 where I disabled almost everything. For which apparently the measurements match to the 2 digits what I can find online, which I can compare since it's much easier to use the same software-hardware combo.
This is not ARM vs x86. It's just the RPI that is crap regarding power management, since by design _they are not even trying_. They just wanted to be cheap. There are many (ARM and other) CPUs that idle even lower than that. If they wanted to be efficient, they would beat the many year old Atom in an instant. Probably already do in (peak) performance/watt.
What x86 chip can idle on 4W when including RAM and the mainboard?
I have some very low power J1900 boards, but even they idle on ~10W.