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aliensporebomb

macrumors 68000
Original poster
Jun 19, 2005
1,907
332
Minneapolis, MN, USA, Urth
I was concerned about using my iMac 27" Corei7 under heavy load for long periods of time.

As an experiment I bought a small electric fan designed for people who wanted to keep cool at their desks in their offices.

fans.jpg


I pointed it at the back of the iMac while it was under load and monitored the results in temperature monitor.

During the middle of the experiment I turned the fan off and then back on.

Take a look at the temperature reduction as a result:

temps.jpg


Your mileage may vary but it is pretty obvious the machine is under less heat and thus less stress as a result. It hardly makes a sound at all and seems to reduce the temps a noticeable amount.


One more thing:
Please note that the extremely high temperatures at the very beginning of the left side of the graph were as a result of me keeping "long term values" history selected in temperature monitor and the very high temps are from my old Mac G5 computer - temperature monitor apparently migrated those temperature recordings when I used the migration assistant to copy my old boot drive from my G5 to the new iMac.
 

bas-macfan

macrumors member
Jun 9, 2010
69
0
I was concerned about using my iMac 27" Corei7 under heavy load for long periods of time.

As an experiment I bought a small electric fan designed for people who wanted to keep cool at their desks in their offices.

fans.jpg


I pointed it at the back of the iMac while it was under load and monitored the results in temperature monitor.

During the middle of the experiment I turned the fan off and then back on.

Take a look at the temperature reduction as a result:

temps.jpg


Your mileage may vary but it is pretty obvious the machine is under less heat and thus less stress as a result. It hardly makes a sound at all and seems to reduce the temps a noticeable amount.


One more thing:
Please note that the extremely high temperatures at the very beginning of the left side of the graph were as a result of me keeping "long term values" history selected in temperature monitor and the very high temps are from my old Mac G5 computer - temperature monitor apparently migrated those temperature recordings when I used the migration assistant to copy my old boot drive from my G5 to the new iMac.

why are people so afraid of high temps? The iMac is build for normal high temps even if it is hot. When to hot the iMac will shut down on its own.
 

surfologist87

macrumors 6502
Aug 19, 2010
273
9
Taking care of your stuff, I like it.
It could make it last longer.



why are people so afraid of high temps? The iMac is build for normal high temps even if it is hot. When to hot the iMac will shut down on its own.
And a BMW is made for you to drive like Satan is chasing you. It will handle hardcore driving, however if you drive it like a normal person on a day to day basis and take care of it, it will last a hell of a lot longer.
 

dwarnecke11

macrumors 6502
Nov 29, 2009
354
0
Yeah, if you're using your iMac to the point of it shutting off due to excessive temps, I wouldn't expect it (or the LCD) to last that long.

However, I'd use SMC fan control before I resorted to the OP's setup.
 

craig1410

macrumors 65816
Mar 22, 2007
1,129
905
Scotland
There is no need for any of this. The iMac is well designed and temperatures are well within safe limits. Ironically, it is the efficient removal of heat via the slot at the back which gives the appearance of excess heat.

Enjoy your Mac and use it fully without worrying about temps.

Btw, I am an electronic design engineer and I don't worry about my iMac temps.

Craig
 

TMRaven

macrumors 68020
Nov 5, 2009
2,099
1
No need to worry about temperature control with the iMac. It has a very good cooling system, and will start to rev its fans up if it has to. You also shouldn't worry about temperature and its impact on lifespan, as both the gpu and cpu are built to operate under high heat. If you don't find the default settings to your liking, you can always control the fans with smc control or other programs-- revving up the fans will not decrease lifespan.

More importantly than actual heat values is the amount of charge running through your cpu. I know a guy who had a tower that ran very, very cool (average cpu temperatures were under room temperature) He kept it on a long video encoding episode, and the temps never got above 35c, but the cpu eventually died because of the large amount of time it had lots of voltage passing through it.
 
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