Just an observation

[EdInk]

PSU AX860i - Noticed that idle power draw sat at 101W (at the wall) when PSU in default mode (zero RPM at low loads - temp recorded by PSU sensor 37^oC).. On setting PSU PWM to 40% temperature drops 26.5^oC and idle power draw drops to 85.6W (at the wall).. any reasons why this it?

[FunkyFeatures]

There are differences in efficiency depending on the temperature. Jonnyguru do "cold test" and "hot test" to test the PSU for efficiency. At a certain point, the temperature will affect efficiency.

Or:

You have less background processes, my idle wattage can alter alot

[EdInk]

4 hours ago, FunkyFeatures said:

There are differences in efficiency depending on the temperature. Jonnyguru do "cold test" and "hot test" to test the PSU for efficiency. At a certain point, the temperature will affect efficiency.

Or:

You have less background processes, my idle wattage can alter alot

After a little research, it appears copper ( used for the transformer windings) has a lower resistance at lower temperatures so less power is required to overcome the resistance.