Reasonable fan speeds for iMac 27"?

hakr100

macrumors 6502a
Original poster
Mar 1, 2011
832
12
East Coast
The one terabyte hard drive in my late 2009 I7 iMac was replaced by apple yesterday. Very good service.

But the hard drive fan speed seems awfully high to me, as indicated by the noise level and the iStat meter. It's running at 4274 rpm. Is this within the normal range?

 
Nov 28, 2010
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Uh, I'd first want to know why the fan speed is so high...is the drive running too hot?
No, I was just too lazy to convert the Fahrenheit to Celsius to check, but as the HDD is only 36° C warm and that is within parameters of 55° C or so, it might be just the SMC that needs to be reset. If that does not help, contact Apple again.
 

hakr100

macrumors 6502a
Original poster
Mar 1, 2011
832
12
East Coast
No, I was just too lazy to convert the Fahrenheit to Celsius to check, but as the HDD is only 36° C warm and that is within parameters of 55° C or so, it might be just the SMC that needs to be reset. If that does not help, contact Apple again.
Thanks...I just tried the first set of instructions in the "reset SMC" procedures,
Command-Option-Escape, then Sleep, then Restart then Shut Down, and
the fan speed dropped to 3200 rpm.

Of course, I have no idea what the HD fan speed should be within a range when I am not working the computer hard.

Anyone?
 
Nov 28, 2010
22,670
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For the HD fan? Really?
Yes. The iMac fans are hardly audible when idle, at least in my 2007 iMac.

What about the rest of the SMC reset procedure? I just disconnected all cables including the power cable for a minute or so and then reconnected power and keyboard and mouse and started the iMac to have my SMC problems solved, though fan speeds were never existent.
 

Spike88

macrumors 6502a
Jan 25, 2010
662
0
900 to 1200/1400 RPM.
Agree. iMac 27" at idle (room temp) is between 900-1,100 range. As temp climbs into 80Fs, then fan RPM increase into 1,200+. Fans above 3,200 - 4,000+ RPM means they are spinning super fast. Up in 4,000+ range means they are spinning way too fast. Don't think I've ever seem my iMac fan speeds above 3,000 RPMs....
 

Sticks16

macrumors newbie
Dec 1, 2012
1
0
Fan Speed Too High

I have the same problem. My 1TB HDD was replaced and now my fan is running at 5400+rpm. Can't work with the noise of the fan. SMC reset did not fix. Am awaiting a technician... Did you solve your problem?
 

hakr100

macrumors 6502a
Original poster
Mar 1, 2011
832
12
East Coast
The problem is or was that when Apple replaces the 1TB drives, it uses a version that does not respond to the internal fan speed control mechanism or code, so the fan runs at full speed.

I found a little software program called "HDD Fan Control" that resolves the issue.

Spoke with Apple about this, the techs agreed the problem was "something" missing from the replacement drives. I don't know if this is still happening with the latest replacement drives.

Good luck!
 
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