iMac Fan Settings

Question

Level 1

8 points

iMac Fan Settings

I have an iMac Late 2011 model Quad Core i7 and 8GB RAM. I use it for gaming, editing, design and everyday tasks.

The ambient temperature varies from 25C - 32C and I installed SMC FanControl to adjust fan speeds because when using my iMac the GPU Diode reaches 72C sometimes and when I touch the top of the iMac (near the mic) the aluminium will be very very hot. I really don't know what the optimum fan settings are. Currently I have 2 settings:

1. 1800rpm for the 3 fans

2. 2000rpm for Optical Drive and HD and 2100 for CPU. I use this when I am going to game or render out something or when my Mac starts to get hotter than 65C.

Below is an screenshot of my current temperatures. If anyone could please tell me where the fan speeds should be and how ho my Mac should be getting it would really help me.

Thanks

Nicky

iMac (21.5-inch Mid 2011), OS X Mountain Lion (10.8.3)

Posted on May 5, 2013 4:05 AM

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Answer 1

Nickybu Author

Level 1

8 points

May 5, 2013 4:05 AM in response to Nickybu

Forgot to mention that I was using the second setting for SMC Fa Control

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Answer 2

den.thed

Level 10

92,896 points

May 5, 2013 9:13 AM in response to Nickybu

SMCFanControl is some what limited in that it relies on you to make good decisions.

I not going to knock SMCFanControl, because I have an Early 2006 Core Duo that still works great today in part because it has never been seriously overheated.

I use a total of 5 Favorite: settings.

1. is for normal winter usage

2. is for normal summer usage (HDD at 2000 rpm)

3. is for watching DVD movies and videos

4. is for exterem editing and rendering

5. is all three fans full out

The two biggest draw backs to using elevated fan speeds are:

1. The need for more frequent air intake cleaning

2. Fan noise above a certain rpm.

------------------------------------------------------------------------

The Temps in your screen shot actually look really good and are slightly lower that what I've seen with those models.

You will probably find that increasing the HDD (which is the largest Fan) and then the CPU fan speeds will help the most. The Optical Drive Fan will only slightly help over all cooling.

IMO two, three or four Favorites: is probably the best way to go. One for normal day to day surfing and light work, and one or two for different work loads.

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Answer 3

Nickybu Author

Level 1

8 points

May 5, 2013 9:17 AM in response to den.thed

Thanks for the help! I've had this iMac since July but haven't opened it up to clean yet and remove any dust. When do you think I should clean the air vents?

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Answer 4

Paul_31

Level 6

14,172 points

May 5, 2013 9:31 AM in response to Nickybu

You can clean the vents using a vacuum cleaner. Air is drawn in along the bottom edge where the speakers and RAM are located, there is circular fan vent behind the stand, and the exhaust is the slot along the top edge at the back. Also you may want to do the CD/DVD/SD Card slot on the side. I do mine once a month with the Mac turned off, so the fans aren't doing battle with the vacuum 🙂.

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Answer 5

den.thed

Level 10

92,896 points

May 5, 2013 10:01 AM in response to Nickybu

Paul_31 is spot on... 😉

I don't have a huge dust problem, but check and vacuum my intakes about 4 times a year.

The 2006 iMac that I mentioned above has only been opened twice in 7+ years. Once at 3 years to upgrade to a larger HDD and once at 6 years to replace the PRAM battery. It seems that a regular air intake cleaning really pays off, because both times I found very little dust accumulation in the air passage ways or on the fan blades.

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Answer 6

Nickybu Author

Level 1

8 points

May 16, 2013 4:40 AM in response to Nickybu

Contacted Apple Support and they told me that it is safe for the temperatures to reach 90 C but if higher there might be a problem.

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Answer 7

WZZZ

Level 6

13,238 points

May 16, 2013 5:03 AM in response to Nickybu

Nickybu wrote:

Contacted Apple Support and they told me that it is safe for the temperatures to reach 90 C but if higher there might be a problem.

That's insane. Don't listen to that.

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Answer 8

WZZZ

Level 6

13,238 points

May 16, 2013 5:24 AM in response to den.thed

I regularly vacuum all the intakes on mine. Recently had an on-site tech replacement of the LCD. He blew it all out, but I was appalled to find lots of dust accumulation on the fan blades.

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