2020 i9 Fan Noise

[MMidnight]

I've been checking properly a couple of machines and my guess is it's not about fan noise but airflow noise through the air vents on the back below the stand. There's a very low noise over ground noise which I understand can be a bit disturbing in a very quiet environment. Of course, considering we're not talking about a faulty fan in a shipped unit.
If you hold your hand against the air vents the noise just goes, so I don't think it's related to the fans but to the air flow.

 

[BuCkDoG]

I've been checking properly a couple of machines and my guess is it's not about fan noise but airflow noise through the air vents on the back below the stand. There's a very low noise over ground noise which I understand can be a bit disturbing in a very quiet environment. Of course, considering we're not talking about a faulty fan in a shipped unit.
If you hold your hand against the air vents the noise just goes, so I don't think it's related to the fans but to the air flow.

That is what I was thinking as well but it’s difficult to verify what people are hearing exactly without being in front of the machine or witnessing it in person.

 

[MMidnight]

Just in case someone is interested .Some figures so you can have an idea what I'm talking about.

Placed my Apple Watch below the iMac at idle (i7 2020 27") measuring 32db of noise in a quiet room. That would be the airflow/fan noise.

Clicking repeatedly the Magic Mouse 2 increased the measure to 38-40db .

Keep in mind a 6db increase is doubling the actual volumen. So you could say a mouse click is actually double noisy as the noise from the fans/airflow. And for example, 20-30db is the "floor noise" you could experience in a library/recording studio or similar.

 

[dsc888]

You may be correct. The fan is I think the only moving part in a 2020 iMac. For the record my BTO i9 with a 5700XT is silent unless I am maxing out the CPU cores. My 2014 MacBook Pro that was replaced with this iMac is much noisier. So is my NAS.

Yeah. I am still SHOCKED that 3 different iMacs can have 3 completely different sound signatures! They were all placed in the same room so the only variable were the computer fans. I know Apple likes to keep their options open by having multiple suppliers just in case but this is quite ridiculous. I truly empathize with owners who say their units are loud and those who claim that their unit is silent or near silent. In one month, I somehow ended up with machines that cover the entire gamut of noise. Wow!

 

[LiE_]

You’ll have the same issue with any configuration, they all have the same cooling solution and a 1200rpm idle fan. Some can’t hear it, but that depends on how quiet your room is. It’s definitely noticeable for me and I returned my 2020 i5. Waiting for the refresh ARM iMac now.

For reference 1200rpm is very fast. On my PCs I run my fans at 400-500rpm on idle and up to 1300rpm when doing heavy loads.

 

[shhh2020]

I have the 2020 i9 10-Core with the 5700XT and it runs silently. I'm in a completely silent room and I don't hear any fan noise.

Really completely silent as in "as silent as sleeping or off"? Really bothered me that a MacBook Pro can actually be not audible at all while my 2020 iMac is constantly, though softly, audible with fans at 1200 rpm.

it's not about fan noise but airflow noise through the air vents on the back below the stand. There's a very low noise over ground noise which I understand can be a bit disturbing in a very quiet environment.

Same here as well. Constantly there.

 

[Donnation]

Really completely silent as in "as silent as sleeping or off"? Really bothered me that a MacBook Pro can actually be not audible at all while my 2020 iMac is constantly, though softly, audible with fans at 1200 rpm.



Same here as well. Constantly there.

I honestly don't hear it. But I'm coming from a 2015 iMac that I feel had constant issues with fan noise at it was always running and drove me nuts most of the time. My office is pretty quiet and I don't hear it but that's not to say that someone else might hear it.