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Why so concerned about heat? Is there a reason?

W

weenterbear

macrumors newbie
Original poster
Jan 27, 2012
8
0
Using MBPs and iMacs, I personally have never been concerned about the heat. It gets so hot that I can't touch the bottom of the laptop and the top of the iMac, but that's due to the mechanism to cool down the inside. (I use both machines for 3d rendering, so I do know how hot and loud it gets.)

To my very curiosity, I see many threads online concerning the heat and the way to cool down the machines. (I've read some crazy ones: drilling extra holes for more ventilation? what a nerve)

Now I think, there must be something that I'm missing. I hope you guys help me understand.

Does the machine run slower if it gets too hot? Or are people trying to stop the machine from shutting down automatically? Does it really happen a lot? (Mines haven't shut off despite of continuous rendering, maybe others do shut off rather frequently?)
 
People don't seem to understand that it's normal for your Mac to get very hot under heavy load. Heat can be a problem in computers that have a poorly designed cooling system, but in Apple machines it's not an issue. Others have concerns about effects on battery life or component lifetime that are based more on misconceptions than facts.
 
When I first started using Macs, I had a cooling pad for my MacBook at all times. Since my first pad burned out, I made do without and have been better off ever since.

I know it's stuck-up, pretentious and snooty, but oh those poor cave-man laptops. When will people ever learn :rolleyes:

hri_Qosmio_X300.jpg
 
For some reason, people freak out if the temperature reading goes over some certain number (the particular number being a subjective thing). I never understod that myself. If the machine performs well and does everything you expect it to do — why even bother looking for potential problems? I mean, you have warranty on it anyway...
 
I own a mid 2011 21.5" iMac and a early 2011 15" MBP and haven't had any heat issues at all.
 
People view high temperatures as if all of the coolant has been removed from their car. They simply don't realise that computer components are designed to handle the heat!
 
miles01110 said:
People don't seem to understand that it's normal for your Mac to get very hot under heavy load. Heat can be a problem in computers that have a poorly designed cooling system, but in Apple machines it's not an issue. Others have concerns about effects on battery life or component lifetime that are based more on misconceptions than facts.
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This!!!

If your computer ever truly overheats, it'll shut itself off. I have yet to see a real overheating thread on Macrumors.
 
Ordinarily I agree that Apple have designed the computers to handle any of the heat generated, however I have found one issue that might be heat-related.

I started noticing what looked like dirt behind the glass, grey 'smudge' marks towards the top left and right of the display mostly (although some in the middle). I took the glass off to clean it but there was nothing there. I booked an appointment at the Genius bar and the guy there said that they're aware that sometimes the display can develop this problem, usually due to heat build-up causing the display to start to develop these odd marks. He said it may be related to the environment in which the computer is used however in my case it sits openly on a big desk in a fairly cool room (ie, not a ventilation issue in my case).

Fortunately, although the computer is over 2 years old, it's covered by Applecare so they're going to replace the display for me however they said they can't guarantee the problem will not re-occur at some point in the future (although they said it would likely be 2+ years minimum)

It's a bit worrying, I'm certainly glad I took out Applecare, the cost of the display alone is £350+ according to the guy at the store.
 
NATO said:
Ordinarily I agree that Apple have designed the computers to handle any of the heat generated, however I have found one issue that might be heat-related.

I started noticing what looked like dirt behind the glass, grey 'smudge' marks towards the top left and right of the display mostly (although some in the middle). I took the glass off to clean it but there was nothing there. I booked an appointment at the Genius bar and the guy there said that they're aware that sometimes the display can develop this problem, usually due to heat build-up causing the display to start to develop these odd marks. He said it may be related to the environment in which the computer is used however in my case it sits openly on a big desk in a fairly cool room (ie, not a ventilation issue in my case).

Fortunately, although the computer is over 2 years old, it's covered by Applecare so they're going to replace the display for me however they said they can't guarantee the problem will not re-occur at some point in the future (although they said it would likely be 2+ years minimum)

It's a bit worrying, I'm certainly glad I took out Applecare, the cost of the display alone is £350+ according to the guy at the store.
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This isn't heat related, its actually dust that gets behind the LCD panel. You can't get to it by removing the glass because its behind the panel itself.

You *can* clean this successfully but thankfully you have Apple care that way if they screw it up they'll replace it ;)
 
My only issue with heat is noise. The hotter it gets the faster the fans spin so the louder the fans roar. I'm not concerned the components will overheat or have a short life. They do have systems to shut the computer down if overheating occurs. Otherwise they are working under conditions they were designed for.

So on Macs I always reapply the thermal paste to make the cooling more efficient and it does make a noticeable difference in how often the fans kick up to full speed.

On my desktop builds I always make the cooling as efficient as possible with large fans and heatsinks while keeping efficient flow patterns in mind. That way their RPM remains low. Even under full load for extended periods of time my gaming rig's fans have never gone above 60% to 70%.
 
chrono1081 said:
This isn't heat related, its actually dust that gets behind the LCD panel. You can't get to it by removing the glass because its behind the panel itself.

You *can* clean this successfully but thankfully you have Apple care that way if they screw it up they'll replace it ;)
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It honestly isn't (that's what I thought it was myself) - I took the glass off, cleaned the back of the glass and the screen itself and the marks didn't go away. The genius guy confirmed it's a screen defect caused by excess heat.

Edit - I just found a fantastic thread (here) which seems to explain what the issue is, it seems to be dust buildup inside the various layers of the LCD display. I really hope they've fixed this problem with the replacement display they're installing this week.
 
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NATO said:
It honestly isn't (that's what I thought it was myself) - I took the glass off, cleaned the back of the glass and the screen itself and the marks didn't go away. The genius guy confirmed it's a screen defect caused by excess heat.

Edit - I just found this thread which seems to detail the fault I've experienced
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You can't get to it by removing the glass, its behind the LCD panel itself and that entire panel needs removed.

My parents iMac has this issue and I had to clean it before. (It also used to happen to monitors when I worked in a desert, only we had to clean those all the time ;) )

There was something I saw awhile back (I can't remember where) that showed how to fix this issue if your iMac had this problem and it basically meant removing the LCD panel, cleaning it, then sealing it with some kind of tape. I never did that step I only cleaned it but cleaning it was sufficient.
 
chrono1081 said:
You can't get to it by removing the glass, its behind the LCD panel itself and that entire panel needs removed.

My parents iMac has this issue and I had to clean it before. (It also used to happen to monitors when I worked in a desert, only we had to clean those all the time ;) )

There was something I saw awhile back (I can't remember where) that showed how to fix this issue if your iMac had this problem and it basically meant removing the LCD panel, cleaning it, then sealing it with some kind of tape. I never did that step I only cleaned it but cleaning it was sufficient.
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Oh I see what you mean now. That's an awful, awful design if dust can get inside the actual panel itself, you'd have thought they would be properly sealed to prevent that. My iMac is a first-gen 27" model, I wonder if Apple have made any changes to the display to prevent this happening with newer models?
 
It's a way of thinking that comes from the PC system-building and overclocking community, most of whom are used to rigging up their own cooling solutions for each and every computer they use.

The idea of mass-produced equipment, built to a single spec, really doesn't register with these people. Partly because they like to think that their 1337 PC hard-hacking skills are still relevant even though they just bought a mass-produced machine off the shelf just like you and me and Grandma.

For the record, out of all the models Apple has built, only a few computers ever had heat issues--and every one of them was an all-in-one with a big, hot, CRT tube monitor. And in every case, it was the CRT that would fail, not the processor or graphics card. (There were also some problems with older AirPort base stations, but I don't count those as computers.)
 
NATO said:
Oh I see what you mean now. That's an awful, awful design if dust can get inside the actual panel itself, you'd have thought they would be properly sealed to prevent that. My iMac is a first-gen 27" model, I wonder if Apple have made any changes to the display to prevent this happening with newer models?
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I think its more of a fluke than anything. I have only seen it on one iMac (and I'm around a lot of iMacs) but it is unfortunate to have happen.

If you are in a smoky/dusty environment its more prone to happen, but even in clean environments (like my parents iMac) it can happen.

EDIT: If anyone knows about the article I was talking about with sealing the LCD can you please post it? I can't find it anywhere : /
 
Heat lets me know the iMac is working.

All electronics generate heat, the fact that Apple uses a lot of aluminum in their cases means this heat will be conducted out to the case. The case provides added cooling allowing for quieter fan usage.

Imagine if they built them to the same shape and size with plastic casings. That heat would still be there, you'd not be able to feel it as much but you would hear the fans trying to get rid of it.



EDIT: I had to take one iMac in for service and Apple asked if we smoked. I don't but did tell them it was for a while operated in a dusty environment. They said " oh that explains all the dust in the cooling system. "

We have one iMac that operates in a very dusty, and heated environment. It is in a room setup for tropical parrots. If you had one you would know of the dust they create. In any case we clean that iMac using a special procedure I developed using air pressure and vacuum.
 
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So it's not like the computer runs slower when heated or something. That many people are worried over so much for nothing?
 
In the old days, Apple made iMac with low heat CPUs, low heat GPUs and other low heat internals. When inspecting iMac boxes from 2009/2010s, one will notice they run very cool. Today, the same outer "all-in-1" iMac box now comes with hotter i5s, i7s, more heat producing GPUs, etc. etc. By default, the insides of today's iMacs run hotter. All because "more / faster / hotter" items are being packed within the same size inner box. And, no additional (improved) venting is being used on their boxes either.

ok. What is not? HDDs love to run between 40 and 55C. Above 55C and they are getting too hot. Into 60Cs too long and its at serious risk of blowing. Heat is very bad on HDDs. I hear GPUs above 75C are getting too hot as well. Higher the heat, the higher risk of something blowing. Its like a factory vehicle & towing thing. Tow a heavy trailer short distance with factory configs and no worries. But, tow a heavy trailer long distance with factory configs and its automatic transmission will blow. Blow from heat overload. Thus, all auto mechanics now state "extra" cooling must installed inside the factory vehicle when towing or being loaded too heavy". Thus, allowing its inner parts to run cooler during "above normal usage". IMO, iMacs (and their current design) is the same. Used as typical home user tasks and NO heat problems. But, put under heavy loads `over and over` and its insides will run hot. IMO, way too hot. Thus, for heavy loads, additional cooling must be installed within the iMac box as well. If I designed the iMac chassis for hotter i5s, hotter i7s and hotter GPUs parts, I would have also installed more cooling openings within its lower and top vents as well. Thus, allow more natural air flow. Based on inspections, the new iMac boxes use the same size venting openings as in the older 2009/2010 iMacs. Hopefully, next iMac box design will have "more" air cooling. Especially if they use even "hotter" inner parts within their next iMac box re-design.

If wondering, I use a 3rd party fan control software within my iMac and configure for 200 RPMs above factory. Currently, HDD is at 40C and CPU at 32C. And, ambient at 18C. Yes. Nice and cool - just the way I like it. And, I like my auto transmission to run cooler when towing as well. Use 3rd party fan control software on the iMac box if you want. Or, run the iMac at factory until it automatically shuts down (which is often called "too late" state). It all boils down to user choice.

.
 
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interrobang said:
If what you say is true, why would you even buy such a badly-engineered computer?
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mmmm…. Guess you read my post in a negative way…. Factory spec vehicles under normal loads don't over heat. But under heavy loads, their transmission (insides) get too hot. Especially when consistently used above typical normal usage. It would be nice if auto industry design their vehicles for consistent above normal loads as well. Let's face it. Auto industry, house construction industry and computer industry design for "typical normal usage". They don't design for above normal usage. Sorry you read my post in a negative way.

.
 
mrsir2009 said:
I've come close. They shut off at about 105C, and I've got my MacBook Pro up to 103C ;)
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I've done it before too :p I had my Macbook Pro on a blanket watching training videos and after awhile the video would stutter and the machine would lag so I'd lift the laptop of the blanket until I could touch the bottom and put it back down and keep watching :D
 
Spike88 said:
mmmm…. Guess you read my post in a negative way…. Factory spec vehicles under normal loads don't over heat. But under heavy loads, their transmission (insides) get too hot. Especially when consistently used above typical normal usage. It would be nice if auto industry design their vehicles for consistent above normal loads as well. Let's face it. Auto industry, house construction industry and computer industry design for "typical normal usage". They don't design for above normal usage. Sorry you read my post in a negative way.
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Put the analogies aside for a second.

If a CPU and/or GPU are running at their maximum capacity (say, running a benchmark) then they generate some maximum amount of heat energy per unit of time. Fans move a set amount of air. Air can absorb a set amount of heat. These are physical laws.

If the thermal regulation is adequate, a computer could run at its maximum, indefinitely, with the temperature never rising beyond some level. If not, the temperature would continue to rise until it overheated and crashed. And in my opinion, any computer that did that would be junk. I would never consider such a machine.

And I have no reason to suspect that my 2011 iMac, or any other Apple product I've ever owned, is that shoddily built.
 
all/most components are able to shutoff or slow themselves down when the temperature gets too high. this creates slower response or your computer will freeze.
With people overclocking GPU's to faster speeds, higher heat levels are easily reached and artifacts can be created because of heat. i'm sure CPU's with high heat levels can have the same results. but there are safe guards to protect the electronics from being damaged. having a cool running machine is always better than a hot one.
 
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