Is my iMac running too hot?

OK, point taken. I see you just wanted to know where I was coming from on this. That's completely reasonable. Just that this is usually so contentious here, with some believing in the gospel that Apple engineering can do no wrong. I'm a bit prickly on it and maybe preemptively defensive. Those CPU cores spiking at 90C don't sound very healthy. Wouldn't want to do that for long. What about the other temps? Drive, power supply?

I certainly don't claim that heat is a good thing but I've done absolutely nothing with my eMac and it ran for six solid years for me and another five years for my son. He finally replaced it several months ago despite the fact that it still functioned the same as it did when new.

I agree, those machines including my previous G-3 (that we used for 8 years before selling) had lots of internal breathing room, whereas the iMac design does not.

@WZZZ - to answer your question

When Ambient was about 21C...

CPU Cores 1-8 max at 90-93C

Drive max 54C

Power Supply Max 75C

I have downloaded and installed smcFanControl, boosted the fan speeds and driving the CPUs hard only gets them up to 74C to 77C. Sounds like a good insurance policy to do this during periods of high load, and to raise the speed slightly during general use.

Sounds good. I'd keep an eye on the power supply too. Fan at the back really does help.

Hi red33m

I would like to applogies for apparantly giving you bad advice, i can really only talk from personal experiance with the iMac's and hardware in general. I have been supporting iMac's ( Mac's ) in an enterprise enviroment for quite a while now and, up to this point have not had any issues with any of the hardware due to overheating. I still believe that it is normal for the hardware to reach 75+ degrees Celcius( under load ) and not cause damage to the hardware itself. That may be poor advice to give to someone else and for that, i appolgise, but it has been my experiance that the iMac handles heat pretty well because of the way the heat is distrubted to the aluminimum chassis.

Due to the nature of the Form factor of the computer, i have always expected the iMac/Mac Mini's to run hotter then something like a Mac Pro, which has a much better cooling setup. Granted the new iMac's may have changed the way the heat is managed, and thus, have not been as efficient as i have found the older ones ( again only from personal experiance) but i think that red33m's machine running at 50 is not too bad.

I also have a 2011 i5 21.5" iMac and the only aspect of this computer that gets extremely hot is the GPU Diode while playing games such as Team Fortress 2. It can get up to 77 C after playing for an hour or two. The other components never really seem to break 55C at most, with the power supply occasionally getting to the low 60s C.

I don't believe it's abnormal for the GPU Diode to get this hot, seeing as this is a brand new computer and I was simply playing some games on it, which it is meant to be able to do (with this year's 3x graphics upgrade)

Is the GPU Diode dangerously hot when it's at 77C? Apple doesn't recommend messing with fan settings, and I personally like having a quiet computer.

Should I be concerned?

Hi Guys

I'm new to iMacs. I've had a Macbook Pro for over a year, and just bought a 27" iMac in May. I've been wondering about the heat as well. I downloaded the iStat Nano widget.

Right now my uptime is 2 hours and 20 minutes.

my temps are as follows

HD: Macintosh HD 50 degrees

GPU A 44 degrees

GPU Diode 62 degrees

GPU Heatsink56 degrees

Ambient 22 degrees

Memory Controller 52 degrees

Optical Drive 49 degrees

My fans are

Optical Drive 997rpm

Hard Drive 1098rpm

CPU Fan 1094rpm

Is this normal? Should i be concerned? Also, I know the fans are running, but is it normal for me to barely hear them at all?

Thanks for the help.

Those temps look fine. What counts are the fans rpms. They should be quiet.