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jasimon9

macrumors regular
Original poster
Mar 11, 2009
184
3
My iMac is really hot!

That is, when I run my hand across the outside of the machine, it is warm all over, and the entire upper portion of the back is what I would call "hot" to the touch. That is, I can place my hand there for a while, but it is uncomfortable.

Is this normal?

I suppose there is a specification for case temps.

In a more analytic vein, iStat Nano shows component temps as follows:

HD: 58
CPU A: 57
GPU: 64
GPU Diode: 68
GPU Heatsink: 64
Ambient: 31
Memory Controller: 58

Compared to what I have seen posted elsewhere, this seems at the high end.

Should I be concerned?
 
nah, it appears fine. My iMac can get pretty hot.

Thing is a beast!

CrackBookPro

thanks for that!

Actually, I would withdraw this thread now if I could. I originally posted it because I searched the forum first for topics on heat, but could not find any. So I started the thread.

But then I searched on Google, and interestingly found several pertinent threads on MacRumors that cover the topic well.

So, if there is a moderator crusing about, it would be best just to blow this thread away, as it is in fact well covered elsewhere.

Note to "built-in forum search maintainers" -- Google finds things much better than your search does.
 
In a more analytic vein, iStat Nano shows component temps as follows:

HD: 58

Assuming we're talking Celsius, that's not a healthy hard drive temperature. Low fifties is tolerable, but 60c is the maximum operating temperature (and temperatures approaching it can cause your platter to warp over time - continual high temp -> cool down cycles, leading your hard drive to an early grave).

+ Is it a 2009 iMac with a 1TB drive by any chance?

All the other components should be fine - mid 60s are tolerable for CPU and GPU, and they will shut themselves down or throttle under excessive temperature loads any way. Your hard drive though is not as 'intelligent' though, which is why I would be a bit worried
 
We get these threads every other day. Top left of the iMac can get very hot - almost too hot to keep your hand on. All perfectly normal.

David - I think you're just unnecessarily worrying our original poster. Virtually every aluminium iMac has its hard drive getting near 60C, yet they have no problems.

Yes, perhaps the hard drive will last 8 years instead of 15 in theory, but so what?
 
Hi guys,

Please don't mess up with your hard drives... I just lost one today because of this ****ing heat here in Paris...

Sure it was my Linux server and it was backed up but even it makes me angry... :-(

The iMac seems ok with the cooling, but my previous MBP was dealing badly with this and I installed a piece of software to speed the fans up.
http://www.derman.com/Download/Special/iMacFanControl.html

So thanks for the "low fifties" tip !
 
David - I think you're just unnecessarily worrying our original poster. Virtually every aluminium iMac has its hard drive getting near 60C, yet they have no problems.

Yes, perhaps the hard drive will last 8 years instead of 15 in theory, but so what?

Ignorance is bliss - once you've had a drive or two full of precious data fail on you, you get a better idea of how incredibly sensitive they are. They are (in essence) mechanical tape drives: and tape, by nature, does not 'behave' very nicely in excessive heat.

Also, drives will be very very lucky to live 8 years - 15 years is completely out of the question, assuming it gets regular use. With a continual heat up to ~60C -> Cool down loop though, I reckon it'll be lucky to scrape 2 years, let alone 8.

And "virtually every" is a misnomer. My previous (2008) iMac had an HD that remained steady at ~38C to 40C. My new (2009) one with a 1TB HD, however, can't keep itself below 50C without having the fans practically maxed.

If the OP also has a 1TB drive, it makes me wonder whether there is some kind of problem being ignored with these drives - either a design issue, or some kind of manufacturing issue with a certain batch of the drives (my one, at least, gets very hot as per the OP, but it has a very erratic temperature profile. It isn't linear, it just heats up for no apparent reason).

Finally, this is not "unnecessary worry". After splashing out for one of these (otherwise brilliant) machines, you want to keep it running for as long as possible - obviously. Ignoring potential problems does not magic them away - it may cause less worry in the short term, but in the long term you could stand to lose a lot of data, or either the entire machine is something major is being overlooked.

"Fix your problems before they acquire weapons of mass destruction"

(To reiterate: The other temps, and the case becoming hot are fine. The hard drive temperature, however, is far from desirable)
 
The aluminum casing actually acts as the heatsink for the electronics and mechanical parts (HDD, CDD/DVDD) inside. So, hot casing means it's doing its job. The trick is to give enough clearance around the case so that heat can be dissipated properly. It would help if there's a nice gradient between ambient room temperature and the case temperature (read: the room is not too hot).

The HDD is the most valuable and one of the weakest components of a computer. Make use of Leopard's excellent Time Machine system and hedge your bet with a double backup scheme (RAID, backup, disk clone, etc).

BTW, your temps don't look that bad.
 
Checking back on the temps ...

I just came back to my machine after it being in the sleep state for a while. iStat Nano reads the following:

HD: 45
CPU A: 38
GPU: 47
GPU Diode: 50
GPU Heatsink: 47
Ambient: 22
Memory Controller: 40

These figures are drastically lower than those that prompted me to start this thread.

I am wondering what the Ambient means -- if it is an attempt to measure the "room temp" or something that would approximate that, then I see a huge difference of 9 degrees warmer in my original post that seems would be an important contributor to the high readings.

Having said that, it is normally between 22 and 27 celsius in my home office.

Some more points:

1. I do use Time Machine.

2. The HD is a 500GB.
 
I too have a very hot iMac, (original alu 2.8 'Extreme', 750GB), slightly more so than the original temps you posted.

Significantly my HDD gets to 60-62°C after half an hour of email/internet browsing.

I've had it in twice now to get the problem fixed because I believe that is too hot, (the iMacs at work average just under 40°C). They have replaced the power supply, logic board and sensor to the HDD. They even reinstalled the software, and still it gets hot.

I'm going for one more attempt; at what point might they replace the machine? [At what point might I give up?!]
 
I'm going for one more attempt; at what point might they replace the machine?

Normally they just replace it whenever they feel it's "right" - it depends what person/store you're in contact with.

The best way, if you really want it replaced, is just to say "I want it replaced". This is exactly what I did with my machine (after only a single repair attempt for a slightly dodgy screen) and whilst they initially present you with "That's not an option right now (etc.)", if you keep on chasing a replacement your issue will be 'escalated' to someone who most definitely will authorise a replacement.

For example, I'm in the UK and when my issue was 'escalated' I ended up talking to some bloke in Canada (presumably some high level person) who authorised a replacement. So they're really good, you just need to get through the lower ranks, and talk to someone who's more in a position to make decisions (I assume the lower level guys are told to always try and put-off replacements for as long as possible, to keep costs down)
 
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