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jennyp

macrumors 6502a
Original poster
Oct 27, 2007
666
363
I'm starting to work with my new iMac (27-inch 3.4 GHz Intel Core i7, 12GB RAM and 2GB video RAM) and I thought I'd try it out with two 23-inch displays attached to the two thunderbolt ports. It works with them well, and I have acres of screen space, but, looking at the iStat widget, everything looks normal except that the GPU Diode is reading 71 degrees C. Is that too much? What could go wrong? Eeek? (The GPU heatsink reads 65 C)
 
Those temperatures are fine. If it was too hot, the fans would speed up as designed. If the fans where not able to cool the GPU enough, the system would shut down to protect itself.
 
Well the machine seems really quiet, so hopefully that's OK. Thanks for that info. So I don't have to worry about these temperatures at all then, if the system is constantly monitoring it all? I thought maybe there might be a temperature level that should worry me, so that I should perhaps disconnect one or both the other displays and give the system a cool-down.

Thank you!
 
We don't live in the 90's anymore (thank an entity of your choice). Computers have gotten smarter and more able to handle higher operating temperatures. Intell iMacs have 3 fans in them. Most of the time they are all running at the minimum speed. But if something gets a bit warm, they'll rev up to remove extra heat. Another thing, the iMac's metal body will get warm/hot. This is normal. Remember, it is a metal body and metal conducts heat very well. In fact, the iMac's metal body helps to passively remove extra heat.
 
I thought I might be over-taxing it, but that's reassuring. Thanks very much!
 
We don't live in the 90's anymore (thank an entity of your choice). Computers have gotten smarter and more able to handle higher operating temperatures. Intell iMacs have 3 fans in them. Most of the time they are all running at the minimum speed. But if something gets a bit warm, they'll rev up to remove extra heat. Another thing, the iMac's metal body will get warm/hot. This is normal. Remember, it is a metal body and metal conducts heat very well. In fact, the iMac's metal body helps to passively remove extra heat.

This. If you want to, you can think of the metal as an large heatsink and if you want you can point a fan at it for extra cooling ;)

But there should be no need to worry
 
The All-In-One design of the iMac box forces its insides to run hotter - compared to an open box design. IMO, the iMac design does need to allow more internal air flow with larger opening in its top and bottom vents holes. Thus, allowing more free-flow air. Hopefully, the next redesign "box" has better cooling.

If you feel the internals of your iMac run "too hot" (for your liking), simply install SMC Fan Control software (available for free @ http://www.macupdate.com/app/mac/23049/smcfancontrol ) and increase its fans by 200 RPMs. 200 RPMs increase is a minor increase and can lower the inside temps by 3-5 C. Sometimes, up to 8-10 C cooling improvement while under heavy lifting tasks. If wondering, I use SMC Fan control within my iMac and its insides are now "much cooler". As we know, cooler insides means longer life and possible less system hangs (same rule applies to vehicle engines as well).

As a minimum DIY "venting improvement" task, simply remove the underbelly memory cover (3 x simple screws). One doesn't see this underbelly area anyway. Removing this cover allows more air flow into its underbelly - which helps cool its insides as well.

.
 
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