iMac Heat Issues

@ maitaimai:

I would have to take it in to the place where they installed my new HD. I am not familiar with iMacs and I don't dare to open it. Has this solution worked for others as to cooling down their system?.
If so, I will call them on Monday and ask them - although I can't stand hauling this monster around - but, I cannot afford nor I would tolerate another HD failure. I have read also of people (iMac Freezing thread) drilling holes, but I believe it to be a very drastic measure. This machine is from late 2007, and I am going to repeat this over and over again: My 2003 Dell Dimension is still working. I don't want to hear that Apples are better than Dell's. Then again, I must have bought a 'bad apple'. 😟

These are my stats after using the computer for about 10 minutes or so:

CPU A 43C
Airport Card 61C
Ambient 26C
GPU 58C
GPU Diode 62C
GPU Heatsink 57C
HD Bay 1 51C
Memory Controller 50C
Optical Drive 44C
Power supply 1 80C
Mac HD 53C

I am going to be able to fry an egg on top of this machine pretty soon. Aghrrr.

Something else to consider if you don't want to worry about getting it replaced again is to get smcfancontrol, so that you can control the speed of your fans, and run your mac cooler. Just speed up your fans a little until they make the temperatures go down to normal.

You're right. That's ridiculous!

Hello Xandraa.

One thing is the harddisk bay and another the meassurement of the harddisk temperature itself.
If your harddisk bay reaches 54ºC, your harddisk should be some centigrades warmer reaching the 60ºC limit. From 60ºC onwards the harddisk is at risk. iStat Menus allows you to read out the hd temperature as well. Probably the harddisk is placed in your iMac next to the power supply and a power supply running at more than 80ºC is an "environmental problem" for the harddisk.
The solution for my problem was simple as reported in the iMac Freezing topic. One of the ventilation holes in the power supply enclosure was covered completely with isolation foam and the other partly. The temperatures dropped more than 30ºC after this operation.

_+(Not that you could even begin to prove that statement)+_

I can accept that your opinion of the definition of "relatively few" is different from mine. You are entitled to your opinion.

However, as proof, I'm satisfied to rely upon the marketplace's continual judgement of what is acceptable given the *alternatives and their prices*. In addition, drive manufacturers continue to manufacture and offer to sell their warranted component with a temperature tolerance range as high as 60C while buyers continue to purchase and use that same product. This leads to the inescapable conclusion that the reported AFR that troubles you is lower than an AFR that would trouble most others enough to halt their purchases. In other words, to most consumers, the failures are seen as being relatively few.

One might suppose that the direct financial costs to the manufacturers (including the *rising shipping costs* of replacements) in dealing with these products that allegedly have more than a relatively few failures would be an unsustainable business model in the face of hard drive prices which continue to decline, forcing the cost of warranty resolution higher as a percentage of the initial sale. How, oh how, do they possibly manage this? Again, perhaps the manufacturers also see the failures as being relatively few.

I will also add a quote from the Section 1 "Introduction" contained on the first page of the Google study link which you so kindly provided us:
"*Disk drives are generally very reliable* but they are also very complex components. This combination means that although *they fail rarely*, when they do fail, the possible causes of failure can be numerous."




_+You would still do well to read+_

Others may be interested to note that your posted quote from section 3.4 of the Google study omitted the very next sentence of the study:
"Overall our experiments can confirm previously reported temperature effects only for the high end of our temperature range and especially for older drives."

and completely ignored the major conclusion of the study (2nd paragraph of section 5 "Conclusions:"
"One of our key findings has been the lack of a consistent pattern of higher failure rates for higher temperature drives or for those drives at higher utilization levels. Such correlations have been repeatedly highlighted by previous studies, but we are unable to confirm them by observing our population. Although our data do not allow us to conclude that there is no such correlation, it provides strong evidence to suggest that other effects may be more prominent in affecting disk drive reliability in the context of a professionally managed data center deployment."


This thread was started concerning 2009 iMac models. Now it contains irrelevant complaints about 2006 non-aluminum iMacs. I'll let others speculate on the relevance of 2.5 year old Google data regarding 2002-2004 dated hard drives to a discussion about 2009 iMacs. I think it's safe to assume that Apple has not been installing 2002-2004 dated hard drives in the 2009 iMacs.


As to your Wiki link quote, let me suggest this sentence selection as more appropriate:
"It is recommended that the operating temperature of a drive not steadily exceed 47 °C, as this may disproportionately reduce its life. This, however, may not be feasible in laptops."

Since the iMac is an all-in-one similar to laptops, and since it seems to be common for many posters here to consider the useful lifespan of their all-in-ones to be 3-5 years, not 5 years and up as with their towers, this would seem to reinforce an acceptance of the status quo. However, that is only at this point in time - considering the speed of change in technology that we witness almost daily.

In fact, due to coming price reductions, 18 months from now I expect most CTO iMacs and notebooks will be configured by consumers with SSDs, rendering this thread obsolete. Too bad most all-in-one buyers have not yet reached the conclusion that it could be worth their while. I expect each one of my next Mac purchases will be SSD configured, and I expect to start re-configuring all my current Macs before year-end. This even though my 2007 alum 24" iMac has not shown any sign at all of excessive heat, and the fact that replacing the MacBook and MacPro drives is such a snap that I have virtually no current risk. Also, I'm not a gamer with conflicting needs.

Message was edited by: myhighway

A well-reasoned response. I had forgotten the final conclusion that high-temp failure was "inconclusive," for lack of a better word. Thanks for pointing that out.

As for "relatively few," your statement was that "there are millions of HDs operating close to 60 C, and relatively few of them fail." My opinion regarding what "relatively few" means is not the issue. Two questions can illustrate my point.

1. In a million hard drives, how many fail in a year?
2. Of those hard drives, what percent were operating at 60ºC?

I'm betting that you do not have access to hard data that can answer either question, unless you work for a company that services millions of hard drives a year (if you do, I'm sure we'd love to get some hard numbers to help us understand the issue more). If I'm right, you have no way of knowing if "relatively few" fail. (If anything, the Google study suggested that more hard drives fail at high temperatures than at low, even if the temperature as not necessarily the cause.) My "prove it" statement, though a bit too confrontational, was meant more that you are unable to back up the "relatively few" claim without providing data over the entire range. I could tell you that "relatively few" people use their Macs for typing papers, but without a baseline to compare with, it's a meaningless statement (am I talking about "compared to PC's?" Do I even know how many people use a Mac for typing papers? Or did I just make an assumption based on limited experience and then draw a faulty conclusion?).

A comment about the "Marketplace's judgment"... It is never a meaningful indicator. After all, people will routinely play lower prices for items with a shorter lifespan. The mere fact that $200-300 PC laptops sell so well (even when they often fail in a short time space, compared to Mac laptops that seem to run forever) suggests that many consumers focus on cost instead reliability. 😉

Again, thanks for the well-reasoned response. I appreciated reading it and appreciated your criticisms. I can only hope that mine above are similarly insightful.

Myhighway,

After a bit more thought, I think I understand what you were saying by "relatively few." For example, if even 10,000 fail out of a million, that could be considered "relatively few" (1%). I was approaching it from the "relatively few fail at 60ºC versus other temperatures." A misunderstanding on my part. My apologies.

It's about heat issues and your opinion that macs aren't affected by heat issues. That's simply not true. More than 80 ºC for an internal power supply is far to much. My iMac had a bad, overheating power supply. And do you really think that a late 2006 model bought in 2007 isn't a reference? It did not last even two years and it's not "reliable" and there are thousands of people affected by these problems. It simply doesn't run forever and ever. It feels like a 350$ peace of "sh...". That's the way things are.

Another question: Am I right to assume that you are a volunteer, myhighway?

Message was edited by: maitaimai

_+your opinion that macs aren't affected by heat issues+_
_+And do you really think that a late 2006 model bought in 2007 isn't a reference?+_

*Kindly refer to my post to this thread - Aug 21, 2009 10:16 AM. I think that was accurate and does not need to be re-stated by me, or by you on my behalf. You are, of course, welcome to your own opinion.*

_+run forever+_

*The opposite of my statements regarding all-in-one computers. Also not reflective of the fact that for more than a decade I have, for good reasons based upon my personal experience, advocated AppleCare. Macs come with a one-year warranty - if that's insufficient for one's needs (sure is for mine), AppleCare should be seriously considered, especially since it covers more than just the Mac.*

All of these discussions I have to assume are based on software which is delivering terribly innacurate readings.

Several posts cite a surface temperature of 80 degrees celcius on their unibody iMacs. That's 176 degrees farenheiht!

Human skin burns at 130 degrees farenheiht, at 176 degrees you'd be getting second and possibly third degree burns simply touching the enclosier. Unlikely to say the least since this kind of temperatures would cause severe damage to most internal components within seconds.

Also, note this quote regarding "Temperature Monitor" a free software product available at Macupdate.com.
"Please note that Apple does not support an official or standardized way of reading out sensor data in Mac OS X (the only exception is the Server Monitor application for the Xserve series). Moreover, there is no documentation or other technical note about the individual function of the sensors. For this reason, the development of Temperature Monitor and Hardware Monitor is very costly because the necessary data has to be determined by reverse engineering and tests run on a variety of computer models"

In short, these programs all use unsupported methods to arrive at their results which makes them inherently unreliable. Put in plain language, yes, it's just a number but what does that number really mean? There is no way to know for sure and so, such tools are simply for reference, not for accuracy.

I don't believe anyone said the surface of their iMac was 80ºC. We are talking about the power supply (internal). It regularly reaches 80º. As for the surface, I have measured mine with a thermometer at 110ºF, high enough to border on painful. The air coming out of the vent at the back was 125ºF. All of this was while idle.

In short, these programs all use unsupported methods to arrive at their results which makes them inherently unreliable. Put in plain language, yes, it's just a number but what does that number really mean? There is no way to know for sure and so, such tools are simply for reference, not for accuracy.

You really have no idea what you're talking about here, do you? Do you understand how heat-sensitive diodes work? Do you realize that it's a relatively simple matter for someone to break a computer apart, measure the data directly from a sensor and then match that to a temperature reading from a thermometer? Heck, that's what ITT Tech was founded on. Just because Apple hasn't released specifications for their hardware doesn't mean that *every single piece* of a Mac can't be taken apart and decoded. Applying basic electronics knowledge is not an "unsupported method." If you had taken even a junior-level class in Electronics in college, you'd understand this. As it is, it sounds like you're still you're still at the "magic" stage, where only guys wearing blue shirts at the Apple store can understand the wonders of them thar computers. Apple may keep some things under wraps, but they don't hold patents on the laws of Physics.

You sir, are a moron!

Firstly, I make my living doing both programming and board level electronics.
I have worked in this industry for 3 decades and know a great deal more about both electronics and software than I would venture 99% of the populous of this forum could ever dream of.

Second, only an idiot would post a comment such as yours without knowing to whom he/she is speaking.

Third, read the ****** posts!

Oh, and by the way, if you've a power supply operating at such temperatures, you've a power supply without any cooling at all.

I'm ignorant? No. You are, despite your ego's urgings to the contrary.

Stop playing at being a tech when clearly you aren't one.

Dear fellow forum members,

I read all input carefully and I'm also informed there's a history of iMacs overheating, especially the PPC-ones.

As you can see below I'm using a PowerMac G5 at home - without any serious problems sofar - and since two months the company I work for served me very well offering me a new 'left over' early 2008 24 inch iMac, foremost used for graphic purposes.

My impression is that the cramped concept of the iMac has clearly a negative influence on temperature control and that the basic fan settings Apple is using are particularly dictated by silent operation over cooling results.
I downloaded iMac Fan Control and after careful adjustements I found it very effective in keeping all critical readings at moderate levels.

Besides Apple's never ending problems with nVidia driver software (the new 'old' iMac fortunaly has the ATI 2600 Pro and I would buy a new ATI card for my G5 any day if available), heath is always considered a serious enemy of any electronic device. Especially components like hard discs, TFT-screens (brown stains or non-removable image persistance; I've seen them all) and graphic cards are affected, certainly in the long run. Therefore I rather like my computers operating at temperature levels as low as possible.

And there's another problem. After installing Temperature Monitor I discovered odd (sticky) temperature readings from one of the cores, so I mailed Mr. Bresink what could be the trouble. He informed me that the specific 2.8 GHz processor in my iMac was exclusively built for Apple and that he couldn't get any technical specifications from Intel relating to those custom made components. What seems to be the problem is that a lot of Intel 45nm Core2Duo processors are suffering from defective sensors in one or even both ⚠ cores, causing the systems regulating software getting confused. Nevertheless Intel passed those crippled processors, clearly accepting the risk both sensors could fail in future.

So, overheating is certainly a serious topic and the fact that some forum members could convince Apple delivering them a new computer should be enough reason for iMac owners to keep their eyes wide open for such issues. Odd temperatures reported by iStat or Temperature Monitor, even if they are not that precise, could be a good indication something is wrong.

Best regards,
Robbert