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iMac SMC Firmware Update 1.1 - Fan Noise - Late 2013 27 iMac

PLEASE for the sake of everyone here, STOP ARGUING about this nonsense. If you claim your machine to be virtually silent after the SMC update, great! However, please provide some more evidence rather than an hearing test. If it is truly silent idle, that means they may have corrected it and I would be thrilled to know that.

Furthermore, I just spoke with Apple yesterday and they assured me it should be completely silent at idle. Thus, there definitely is a problem with the fans after the firmware update for many of us here.
 
MacOG728893 said:
The fan is right around 1200RPM. I am just going to do a clean install. I have been less thrilled with my overall purchase so far.



Nope, it finished indexing very quickly. I have 512GB SSD.
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If your iMac fan is at 1200rpm, I suspect then what you're noticing is that you *think* your iMac is louder because the update made you suspicious of things breaking, for whatever reason. 1200rpm is 1200rpm, and that's the standard speed. There's no way around that.
 
WilliamG said:
If your iMac fan is at 1200rpm, I suspect then what you're noticing is that you *think* your iMac is louder because the update made you suspicious of things breaking, for whatever reason. 1200rpm is 1200rpm, and that's the standard speed. There's no way around that.
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That's all fine and dandy. The problem is before (a few days) the update, there wasn't a single whisper from the computer at idle. After the update, the fan is now audible. See the problem here?
 
MacOG728893 said:
That's all fine and dandy. The problem is before (a few days) the update, there wasn't a single whisper from the computer at idle. After the update, the fan is now audible. See the problem here?
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No, I still don't. It's not possible unless your fan crapped out or the bearing got ruined somehow. 1200rpm is 1200rpm. I tend to think you're just noticing what was already there. I realize you won't agree, but it's really the most logical answer.
 
Chippy99 said:
Apple themselves do not claim the iMac is silent (because it isn't), even when idling. The fact is many (most?) people can hear the faint air rushing noise. Just because you cannot, does not mean it is therefore silent.
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That's a negative, I don't understand what's up with every one arguing telling us ours are not silent, I'm sure it emits some noise, mine just at a level no human can hear.

There's nothing wrong with my hearing, my room is quiet. I can place my ear right up to my iMac and still not hear any sounds it makes there for MINE is silent. In fact after having my MacBook Pro from 2009 I thought the fan would be similar being audible, spinning up under stress etc.. Fact is I've yet to hear anything from my iMac, at least at a level that I can hear and I sit close to my 27" it would make you cringe!

I think some people need to blow the dust or stop blocking there vents :/
Other wise I'm sorry to hear your iMacs produce so much noise.:confused:
 
WilliamG said:
No, I still don't. It's not possible unless your fan crapped out or the bearing got ruined somehow. 1200rpm is 1200rpm. I tend to think you're just noticing what was already there. I realize you won't agree, but it's really the most logical answer.
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That's exactly my point. I am not arguing that 1200RPM is the normal fan speed, I am saying that my fans before the update were perfectly 100% silent.

It may indeed have messed up the bearings or something of the sort. I used it in an extremely quiet environment for 3-4 days. Right after the update, I immediately noticed the shift in sound. That is right when I posted here.

I am not debating whether my fans are running at the right speed or not, my point is that the update caused them to be audible, which they were not before.
 
MacOG728893 said:
That's exactly my point. I am not arguing that 1200RPM is the normal fan speed, I am saying that my fans before the update were perfectly 100% silent.

It may indeed have messed up the bearings or something of the sort. I used it in an extremely quiet environment for 3-4 days. Right after the update, I immediately noticed the shift in sound. That is right when I posted here.

I am not debating whether my fans are running at the right speed or not, my point is that the update caused them to be audible, which they were not before.
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I'm not really sure what you're looking for, then. Take it to Apple, and demand a fan replacement, then. Nobody can tell you what you're hearing, clearly.
 
WilliamG said:
I'm not really sure what you're looking for, then. Take it to Apple, and demand a fan replacement, then. Nobody can tell you what you're hearing, clearly.
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I realize that much. The whole point of thread was simply to see if others were experiencing the same problem as me.
 
So back on track

My new iMac turned up yesterday, in a mavericks box.


firstly it has the electrical crackling / chirping at low brightness. However the screen its near damm perfect!

The fan is not as loud as the one it replaced, by loud i mean a constantly rattling / ticking. So my old iMac was clearly faulty.

I can hear the airflow of this one too which i class as normal in my quiet office, but i can hear very little to no fan rattle so i'm quite pleased.


Despite the annoying electrical crackling at low brightness i'm thinking i might keep this one because the screen is very good and fan noise is minimal.

I just wish they could have better testing on their iMacs. They are either using cheap components in the PSU or panel or cheap fans. If you work in a quiet environment, with very low background noise outside and perhaps have sensitive hearing i'm sure you will pick up on these quirks.
 
My replacement's fan seems to be on as wel during idle. The two previous i5s almost never ran at idle, or I didn't hear them at least. I'm not sure if this is because the new one is an i7 or not? I did notice notice this last night...the fans are slightly on....just enough to hear and feel air being circulated. I'm not returning this one because everything else is good. The noise isn't a grinding or rattling sound, so it doesn't bother me much.
 
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bartonjm said:
My replacement's fan seems to be on as wel during idle. The two previous i5s almost never ran at idle, or I didn't hear them at least. I'm not sure if this is because the new one is an i7 or not? I did notice notice this last night...the fans are slightly on....just enough to hear and feel air being circulated. I'm not returning this one because everything else is good. The noise isn't a grinding or rattling sound, so it doesn't bother me much.
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The fan is always on at idle.
 
I've just figured out what is rattling on these fans.

The GPU fan

When i boot my computer i don't hear anything. After a certain period of time the GPU fan must turn on. I can force it by running open gl in cinebench to heat up the card.

Can't believe it. I have the 750m 4GB card.

Therefore this isn't likely to be a Apple related issue or an isolated issue. However both iMacs i've had have this noise. 1 is louder than another.

Thing is i could do with this card as i plan to play BF4 and think the 2GB card won't be fast enough?

Also is there anyway to force discrete graphics?
 
I thought that there was only one fan. I have fan control installed and it only lists one "main" fain.
 
iraklis9 said:
I thought that there was only one fan. I have fan control installed and it only lists one "main" fain.
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Yes i saw only 1 fan too but don't GPU's have their own on board fan that activates at a certain temperature.
 
Wow, lots of new info! As far as Apple goes, I have not gone in yet, just too busy right now.

It is weird, when the computer first starts, the fans are silent, then they kick on. Also, went I put the computer to sleep, the fans often keep running for a bit. This is quite annoying.
 
The fans on mine kick on ~5 seconds after I hit the power button. Always have. Now if there is a Hard Drive that kicks on first then the fans (mine is ssd). No fan on the 775 GPU that i know of

Here is a teardown showing the 775M 1G option - no fan.
 
I have contacted apple support and they said to take it to a service centre for service. I'm a bit reluctant though.
 
I got my 27 2013. After SMC update I have no issues with fan noise. All good.

Ps- i7, 256ssd,780m version
 
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