Breakdown of motherboard power consumption

[birthdaymonkey]

Recently I decided to make a spreadsheet to calculate the actual power draw for a typical computer. I know there are PSU calculators aplenty, but base on what I've learned over the years, these tend to significantly overestimate the power requirements of a computer.

So I'm trying to be as granular as possible in my spreadsheet -- I'm researching each component (CPU, GPU, memory modules, storage devices, various expansion cards...)

The one thing that's really hard to figure out is motherboard power draw. I know that there will be a wide variance from model to model since every motherboard offers its own set of features. So I'm hoping someone with more knowledge than I about individual motherboard components might be able to offer some insight.

Which ICs, ports, etc. draw power, and how much might they draw under a typical load.

So far, I've found that according to Intel's data sheet, the Z390 chipset itself draws just 6 watts. Then there would be the ethernet controller, (optional) wifi chipset, audio codec, super i/o, a few LEDs (or a bunch of them on some models). Is there anything else on a motherboard that consumes power?

I've seen total motherboard power draw estimates ranging from 20 to 100 watts, but that's a wide range, and not necessarily up-to-date.

 

[piasabird]

Different kind of motherboards may draw power at different rates. I recently built an Asrock Deskmini 310. It supports 8th Gen Intel CPU's and maybe 9th Gen with a Bios Flash. It is a Mini-STX 5 by 5 Motherboard that supports CPU's with 65 watt thermal rating and uses Sodim DDR4. It also comes with a Wireless kit and has a M.2 slot. It has no PCIE slots and a limited amount of USB (One type C) slots. You can add 2 USB2 ports, and it can come with a Comm Port.

Supporting less peripherals should result in less overall power usage.