How accurate is the power supply voltage rail reporting?

[gameinn]

For example if hwinfo says my 12v rail is 11.928v how accurate is this to actual voltages being supplied if proper measurements were taken with hardware? Asus x570 motherboard if that helps.

 

[Martin]

Accuracy depends on sensor chip used, for later ones it's 2-8 mV. It also depends on placement on the mainboard, but this is specific for each board.