The next chapter of this adventure, this has to do with the measurement error of onboard motherboard voltage sensors.
All three DMM at the previews test, they are unquestionably more accurate that any low cost voltage sensor.
5V Rail = 5.133 V / 5.1V due MB sensor
12V Rail = 12.120 V / 12.096 V due MB sensor
3.3V Rail = 3.329 V / 3.363 V due MB sensor
The test it is performed with the PC at idle state, windows power management setting = high performance
PSU watt from mains =
104.5W Previously the CORSAIR CX750 = ATX 2.4 this as more modern it was able to limit down power consumption at
96.5W HIPER this is older product = ATX 2.2 and as such it has a lower power efficiency, and the outcome this is
8W of higher consumption.
My PC system this were also tested at gaming mode
for several hours, max recorded consumption this was
271 Watt, but the real consumption it is higher than that.
Low cost plug-in AC power meter, they are very slow, slow sampling interval does not help at all regarding accuracy.
Even with out an comparison with a much faster professional power meter, I am aware that Min and Max consumption values these are always in significant error, along with the power factor.
INTEL speed-step this is technology helping the CPU to mostly stay cooler by lowering CPU frequency, lowest at my CPU this is 800MHz and 3700 MHz the max (all cores active).
INTEL speed-step this gets activated at windows power management setting =
Balanced.
The fast switching of CPU frequencies, this is enough to increase further the measurement error of any budget plug-in AC power meter.
Especially Power Factor measurement this is now at huge error.
The conclusion, this is that a power meter for PC PSU evaluation, this must offer sampling rate of nothing less than four times per second.
Motherboard Voltage sensors measurement error, this has a lesser importance, when the PSU this has be inspected by more reliable tools.