Corsair RM 650 (2021) Question about the operation of the fan

[zgl7]

Hello, for a few days I have been in possession of the RM650 2021 power supply and I have a question what the fan works in this model. Well, I noticed a thing in its operation. Well, when the system is loaded with a temporary large load, for example, including a furmark program even for 5 seconds, it generates a large demand for power, so the fan turns on, which is understandable.

But I noticed a case that even after such a temporary 5 sec load only and closing the loading program. the fan turns 20 minutes each time. even if the load is only temporary. as if it was programmed that the fan rotates at least 20 minutes after detecting this load

It looks like programmed for me because I checked one more thing, if I load the system for 15 minutes, the fan will also turn off after 20 minutes of work. ie 5 min after the end of the load. if the load lasts longer than 20 minutes, the fan will work all the time and it turns off for a while after it turns off the load

and my question is whether this is how it is supposed to work or someone who is dealing with the new RM 2021 series could say whether this behavior is normal?

Finally, sorry that my English is not my native language

[jonnyguru]

Yes.  It's called a hysteresis.  The fan drops down to the lowest RPM, but doesn't shut off.  It does this to make sure all heat is evacuated so the PSU fan doesn't "pulsate" if the load or temperature are on the precipice of the fan turning back on again.

[zgl7]

24 minutes ago, jonnyguru said:

Yes.  It's called a hysteresis.  The fan drops down to the lowest RPM, but doesn't shut off.  It does this to make sure all heat is evacuated so the PSU fan doesn't "pulsate" if the load or temperature are on the precipice of the fan turning back on again.

Thank you for your answer
I couldn't find any information on this subject anywhere. 
so as I understood correctly this is a perfectly normal programmed fan operation. that even after such a momentary peak in the load
 on the power supply, even when the load drops, the fan is to rotate for these 20 minutes waiting for what will happen 
before it goes into a passive state. this is to prevent the fan from constantly turning on and off when generating such temporary loads