iMac 27' fan too loud?

anywhere08

macrumors newbie
Original poster
Sep 6, 2009
25
0
Just got a 27' i7 iMac but noticed the fans were really loud. I downloaded iStat and got these for the fans.

Optical Drive: 3414 rpm
Hard Drive: 1097
CPU Fan: 3861 rpm

is that unusual? any solutions?

thanks :apple:
 

anywhere08

macrumors newbie
Original poster
Sep 6, 2009
25
0
Don't think so. Only thing running was safari. It's been like that since I turned it on.
 

Scott6666

macrumors 65816
Feb 2, 2008
1,331
468
Very not normal. You can try the reset PRAMs and SMC path but it sounds very unusual to me.

Even if you have one of your cores running full blast (there's an airport bug that does that) I don't think mine ever got that high.

I would exchange.
 

anywhere08

macrumors newbie
Original poster
Sep 6, 2009
25
0
OP, have you looked at the 'Activity Monitor' to see if any processes (Safari) are maxing out CPUs?
I check out the "Activity Monitor" and there was nothing that was maxing out the CPU's.

Very not normal. You can try the reset PRAMs and SMC path but it sounds very unusual to me.

Even if you have one of your cores running full blast (there's an airport bug that does that) I don't think mine ever got that high.

I would exchange.
I reset the SMC and it is still the same. Should I just contact apple?
 

anywhere08

macrumors newbie
Original poster
Sep 6, 2009
25
0
Update: Called apple and found out my product is defective and they are sending me a new iMac. Apple has great customer service. :apple:
 

jeilers

macrumors newbie
Dec 31, 2009
1
0
Update: Called apple and found out my product is defective and they are sending me a new iMac. Apple has great customer service. :apple:
What did Apple say was defective? I have taken my 20" iMac into the Apple store 3 times for this same issue (CPU fan runs at max speed ~ 3800rpm) and they have not been able to solve it.

Any info you have would be great!
Thanks!
 

GugGog

macrumors newbie
Dec 11, 2009
10
0
I had this problem with an I7, which was a "faulty sensor" -- my CPU fan spun up to 6500rpm (!!!) from idle, constantly, over a period of 40 minutes, and stayed there, roaring at me.

It was replaced. I now have an I5 and a base model 27 (dual monitors) and can't hear ANYTHING from them. This, I believe, is how they are supposed to be. No fan noise. No HD noise. Nothing. Bliss!
 

hogo

macrumors regular
Oct 3, 2005
211
93
so. cal
what are average fan speeds when fairly low usage? Ever since i put an ssd in my drive it seems as though it's louder. iStat:

optical: 2250 rpm (this is where my ssd is)
HDD:1099
CPU:938
 

SteveW25561

macrumors newbie
Jan 29, 2008
4
0
I just got my shiny new 27" i7 iMac. While I love its display, I find the fan noise noticeable (but not super loud). It’s a bit annoying, but in my searches I can't find the 'normal' values for the fans. I recognize it isn't the crazy 3000+ rpms others have reported but I can't find normals.

I'm running iStatMenus and here are the temp reports:
CPU temp: 42C
Ambient temp: 22C
HDD fan 1414 rpm ** note: I've taken out my HDD and installed an SSD and shorted out the temp sensor (other posts indicate if you don't do this, the HDD fan goes nuts).
CPU fan: 1699 rpm
Optical drive fan 1920 rpm

CPU loads: 5/0/6/0/2/2/4/0 %

Notes:

* This isn't the HDD: again, I removed the HDD and replaced it with an SSD, shorting the HDD temp sensor (not doing this results in the HDD fan going very fast - see posts on this site for info).


* My user directory is located on an external FW 800 drive
* No disk in the optical drive
* Sound coming from the lower left of the display (CPU fan intake)
* CPU temp is contantly around 40-50C, not much higher
* I'm sure this a CPU fan issue, and while the noise isn't very loud, its definitely noticable. It goes up to around 2000 rpm during mild activity like watching YouTube or using iPhoto and is definitely more noticable.
* I've done an SMC reset to no avail


IS this a normal CPU fan speed (1600-1900 rpm)?
Do other i7 27" iMac owners hear the CPU fan? I'd like to separate this from i5 iMacs since the processors are different.
 

msw123307

macrumors 6502
Mar 25, 2007
433
0
I can't speak to the actual fan speed #'s, however, I can verify that the fans are indeed loud. I had a couple i5's previously - and the HDD's were very annoying, but I didn't really hear the fans. In the i7 I've used more recently - I notice the fan noise much more, and it is annoying too. But nothing when compared to the clicking of the i5 HDD.
 

WilliamG

macrumors G3
Mar 29, 2008
9,086
2,547
Seattle
I can't speak to the actual fan speed #'s, however, I can verify that the fans are indeed loud. I had a couple i5's previously - and the HDD's were very annoying, but I didn't really hear the fans. In the i7 I've used more recently - I notice the fan noise much more, and it is annoying too. But nothing when compared to the clicking of the i5 HDD.
No way! Something is definitely wrong with your computer then. The fans are completely silent in my silent room. Under normal idle use, these are the fan rpms for an i7 iMac:

CPU 939rpm (between 937rpm and 940rpm is reported by iStat)
Optical drive 1000rpm
Hard Drive 1100rpm

My i7 is completely silent, and my CPU idles at around 31-34C. I also have an SSD in my iMac, and that should set the fan speed to 1100rpm. Any other speed and it means something is wrong. It should ALWAYS be 1100rpm if you shorted the cable correctly.
 

SmugMac

macrumors regular
Sep 25, 2009
135
0
My i5 based iMac is near silent. Sometimes I can hear the hard disk working but that's only during the initial boot / log-in...
 

56oval

macrumors newbie
Jan 27, 2010
2
0
Just got a 27' i7 iMac but noticed the fans were really loud. I downloaded iStat and got these for the fans.

Optical Drive: 3414 rpm
Hard Drive: 1097
CPU Fan: 3861 rpm

is that unusual? any solutions?

thanks :apple:
FWIW, I found myself with those same numbers. Turns out it was caused by installing "Fan Control." It turned the speed up becuase I don't think it was designed to work with the new i5/i7 iMac.

Uninstalling it and resetting the SMC fixed the problem. I'm now back down in the 1000-1100 range at idle.
 

56oval

macrumors newbie
Jan 27, 2010
2
0
What did Apple say was defective? I have taken my 20" iMac into the Apple store 3 times for this same issue (CPU fan runs at max speed ~ 3800rpm) and they have not been able to solve it.

Any info you have would be great!
Thanks!
Did you ever install Fan Control by Lobotomo Software?

It screwed mine up and I was getting two of the three fans maxed out all the time. Doing a complete uninstall as described on their site, and resetting the SMC fixed it.
 

ugp

macrumors 65816
Jan 7, 2008
1,223
3
Inverness, Florida
My fan will start spinning full RPM out of no where it seems. I turn off the computer and back on it goes away. I will have to check to see the next time it happens if a process is running in the background.
 

BruceKayleen

macrumors newbie
Jun 15, 2011
1
0
2 iMac 27", only one loud mouth!

I've got (2) 27" iMacs in the same room. One is a very well behaved i5 and the other is an obnoxious i7. I was having the same problem as others are reporting here with the i7's fan going off. I moved the machine away from the wall to make sure it wasn't an airflow problem. That seemed to remedy 90% of the problem. The other 10% seems to only happen at about 5 in the morning (our home office is in our bedroom). Apple is about to hear it...
 

50548

Guest
Apr 17, 2005
5,039
2
Currently in Switzerland
My 2011 27" i7 fans have never gone beyond the following:

1000
1300
1000

And by the way, OF COURSE you're gonna hear some whirring/hum in a completely silent room...iMacs DO have fans and hard drives, you know.

The only thing that kinda bothered me in the beginning was some sort of pulsating hum coming probably from the power supply, which only happened when I connected my external FW800 HD (also with USB 2.0) - it could be some energy oscillation, but I believe my table may have some resonance effects as well...

Even then, nowadays I can barely notice that and am completely happy with my machine...I still have 1 year of warranty anyway, so will take it to assistance in case my abnormal aversion to noise returns.
 

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