Total power usage of a system

[PowerT]

I've my PC connected to a power meter and it draws around 235 Watt.
In HWiFO I looked up the power usage of various components.

117 Watt CPU Pakage Power (Ryzen 9 5950X)
5 Watt GPU ( Radeon 570)
5 Watt Power (Input) motherboard ( Gigabyte X570S Aero G)
105 Watt Power (Input) motherboard ( Gigabyte X570S Aero G)
--------- +
232 Watt

The 232 Watt total aligns perfectly with my power meter.

Am I right concluding the motherboard itself uses 105+5=120 Watt.
What is included in that number?
Memory
SSDs
HDDs
Stuff connected to USB ports
The motherboard itself


I'm on a "mission" to reduce power consumption. Partly to cut my power bill but mostly to reduce heat, which needs to be removed from my case with noisy fans.
Are my conclusions correct?

 

[PowerT]

Same system closer to idle

35 Watt CPU Pakage Power (Ryzen 9 5950X)
3 Watt GPU ( Radeon 570)
3 Watt Power (Input) motherboard ( Gigabyte X570S Aero G)
22 Watt Power (Input) motherboard ( Gigabyte X570S Aero G)
--------- +
63 Watt

My power meter shows 113 Watt.
What causes the 50 Watt difference?
Inefficiency of my PSU? (can't remember the details but it has a platium rating)

 

[Martin]

It's not possible to provide accurate total power consumption unless the system features an intelligent PSU with power monitoring or PSys.
Otherwise the numbers you get cover only a limited set of components and/or their rails.
The Power (Input) that you include in your calculation actually covers only a single rail for the CPU. So your math is wrong and you're adding a part of the same value twice.
To sum it up - in your system the remaining power is unknown and cannot be measured by the system itself.