Does the fan ramp up under startup on imac 2020?

[LadyNinja]

2020, i7, 5700 16gb

Im counting maybe 3 different issues on the fan. Fan replaced on the first issue, came back with another. But this one im about to ask, have always been there.

Is it normal for the fan to ramp up (higher than idle noise at 1200 rmp) under startup and wakeup from sleep? It start while on the black screen. It needs to be in sleep mode for some minutes.

Can someone please have me in mind when youre turning on the machine? Would highly appreciate it. Custom couldn't answer my question. I have already had it in for repair once..

 

[wilberforce]

Edit: OK I just tried restarting my iMac (i7, 2020, 5500XT, 32GB) several times and listened to the fan carefully to hear exactly what it does, which is:

Push back button to turn on.
After about 1 second, startup chime, but no fan yet.
After about 5 seconds, fan starts, making a soft clicking noise.
Fan spins up to slightly faster than idle, I would guess to about 1500 rpm for a few seconds.
After about another 5 seconds fan slows to idle (1200 rpm)
After about another 10 seconds login screen displays

It also does something similar after waking from sleep (after the fan has turned off):
Wake from sleep
After a few seconds, fan starts, making sort of clicking noise
Fan spins up to about 1450 rpm (per MacsFanControl in menubar) for a second
Fan slows to idle (1200 rpm)

The "clicking noise" only happens for the first half-second when the fan is starting up, after that there is only the soft whooshing sound of the air passing though the vents. These sounds are very soft - I can only hear them with my ear near the back vent.

Hope this helps

 

[LadyNinja]

Edit: OK I just tried restarting my iMac (i7, 2020, 5500XT, 32GB) several times and listened to the fan carefully to hear exactly what it does, which is:

Push back button to turn on.
After about 1 second, startup chime, but no fan yet.
After about 5 seconds, fan starts, making a soft clicking noise.
Fan spins up to slightly faster than idle, I would guess to about 1500 rpm for a few seconds.
After about another 5 seconds fan slows to idle (1200 rpm)
After about another 10 seconds login screen displays

It also does something similar after waking from sleep (after the fan has turned off):
Wake from sleep
After a few seconds, fan starts, making sort of clicking noise
Fan spins up to about 1450 rpm (per MacsFanControl in menubar) for a second
Fan slows to idle (1200 rpm)

The "clicking noise" only happens for the first half-second when the fan is starting up, after that there is only the soft whooshing sound of the air passing though the vents. These sounds are very soft - I can only hear them with my ear near the back vent.

Hope this helps

Thank you so much! Appriciate it!

The clicking noise i havent heard.
But the other seems to behave similare. But i can cleary hear the fan going high from sitting position, around 1m.
But but but, i forgot i can monitor the fan after wakeup! I should then see the speed when it behaves this way. Good mentioned!

Oh and i forgot to mention. The fan does NOT ramp up when restarting. Machine needs to be turned off, wait a little before turning on.
This right there makes me wonder.... Is that odd or normal....

 

[wilberforce]

Thank you so much! Appriciate it!

The clicking noise i havent heard.
But the other seems to behave similare. But i can cleary hear the fan going high from sitting position, around 1m.
But but but, i forgot i can monitor the fan after wakeup! I should then see the speed when it behaves this way. Good mentioned!

Oh and i forgot to mention. The fan does NOT ramp up when restarting. Machine needs to be turned off, wait a little before turning on.
This right there makes me wonder.... Is that odd or normal....

One more thought: just because your fan does not behave exactly the same as my fan, does not mean it is not "normal." There may be a variety of behaviors, dependent on temperature and other parameters, that are all normal.