The cooling system in the 27" 2012 iMac is nothing short of brilliant.

[themomopan]

Will try rendering 4K Footage that is color graded soon! Let you know how cold or hot it runs

 

[Macman45]

The exhaust vent is under the hinge, and there's a single fan that pumps air out of there at a fair old clip. The air intakes are on the bottom.

I have the i5 with 680MX and I've been running it at high power for hours in Planetside 2 - you can definitely hear the fan at high load, but it's pretty quiet (practically silent compared to a MBP fan), and it's almost totally silent when at low load.

The back of the machine is hardly even warm after hours of heavy gaming (planetside 2 is no slouch and taxes the CPU and GPU heavily), except around the exhaust vent as you would expect.

It's remarkable.

I can't wait to get mine....My current one gets really hot at times under high loads...As I said, X-Plane 10 64 bit really works it hard. A cooler Imac will be a blessing.

 

[GrammyPuter]

Good to know

This is good to know, since I just burned out my second hard-drive on my 2009 27" iMac, and have just been advised to replace the cooling system (300-500 dollars.

 

[VongolaXEspada]

Yeah I own a Imac 2011, 3.1ghz, and it's not to hot or to cold, its warm, sometimes it is hotter than I want. I've owned computers since the early 90's and i have noticed, that computer do not last if they are warm/hot, the colder they are the longer they will survive. My previous laptop HP laptop, i've had for 7 years and it is still kicking and I've been using a laptop cooling pad ever since I bought it. I am researching for a good cooler, for an imac, can't find any at all, if someone could recommend me something, because the imac is so warm sometimes....Only thing I did was add an additional 8 gigs of ram to the existing 4, so it is now at 12GB.

 

[Gebekophli]

The reason for the lower operating temperatures in iMac 2012 is, that the hot side of the cooling system has been extremely reduced (beyond of the heat pipes) and the warm air is blown directly on the back.

Before 2012, the warm air side beyond the heat pipes was performed through the whole upper half casing and there was individually an incorrect warm air flow back and some leaky counterflow heating operations as "devil circuits".

 

[Arfdog]

I really, truly believe this deserves its own thread. Yes, the 2012 iMac design sacrifices some things to achieve that thin edge, but its cooling is not one of them.

I had a 2009 i7 27" iMac, and that thing ran warm. The top of it would be a toaster oven whether busy or idling. It was baking hot.

By comparison I've been using my loaded 2012 iMac (i7/32GB RAM/Geforce 680MX) all evening and the thing is actually cold everywhere. Right, it's not lukewarm - it's COLD. Whether you love or hate the new design, there's no question Apple has the temperature issue addressed with this 2012 model.

Bravo, Apple. Bravo.

Told you! lol