Do Imacs overheat?

Yogakun

macrumors member
Original poster
Jul 28, 2010
50
0
Hi,

I just curious if Imacs overheat. How do you know when they are too hot. I'm playing Star Wars The Old Republic MMO and or dual screen photoshop. Either or seems to feel like the Imac runs hotter. I hear no fan, but just wondering? Should I be careful and concerned? Usually I don't care because my PC desktops are well ventilated or have room, but this is my precious small enclosed Imac. :D
 

Intell

macrumors P6
Jan 24, 2010
18,886
380
Inside
iMacs do not overheat. They have three fans that rev up if it gets too hot. If the fans are not able to cool the computer down, the iMac will shut itself off to prevent damage. Aluminum iMacs always feel warm or hot to the touch. This is because they are made of metal and metal is a good heat conductor. This is also why Macbook Pro always feel very hot. In fact, the iMac's body acts as a giant passive heat sink. It is all normal and nothing to worry about.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,419
767
The vast majority of Mac models do not overheat. The Intel processors used in Macs are designed to automatically shut down to prevent damage if they truly overheat (around 100C/212F - 105C/221F, depending on your processor). iStat Pro will give you accurate readings of your temps and fan speeds, among other things.

Unless there is a rare defect in a Mac, most temps are well within the normal operating range, considering the workload being put on it. Websites with Flash content, games and other multimedia apps will put higher demand on the CPU/GPU, generating more heat. This is normal. If you're constantly putting high demands on your system, such as gaming or other multimedia tasks, expect temps to rise and fans to spin up accordingly. It's just your Mac doing its job to maintain temps within the normal range.

Your fans are always on when your Mac is on, spinning at a minimum of 2000 rpm (for MBPs) or 1800 rpm (for MBAs, MBs and minis). They will spin faster as needed to keep temps at a safe level. If they're spinning up without increased heat, try resetting the SMC. PRAM/NVRAM has nothing to do with these issues, so resetting it will not help. Also, make sure you don't block the vents, which are located at the rear, near the hinge.

Learn about the fans in your Mac
Apple Portables: Operating temperature

For Flash-related issues:

There is not an overheating problem with Mac models. There is only a perceived overheating problem. That's partly due to the fact that the aluminum casing transfers heat better than some other materials, so they may feel hotter to the touch than computers made of other materials. Because a user is unfamiliar with the heat normally generated by a Mac doesn't mean there's a problem with the Mac. Only on rare occasions is there a defect that causes true overheating.
 

dh2005

macrumors 6502a
Jan 25, 2010
907
0
iMacs do not overheat.
Well, I didn't have the cause identified definitively but, when playing Crysis on a 2010 27" iMac, the final boss fight caused my computer to lock-up. The internal fans were blowing a gale - noisiest I ever heard the machine operating - then the graphics froze, the sound died, and I had to switch it off with the power button. The top of the machine was uncomfortably hot, when I checked.

In my semi-educated opinion, it overheated.
 

dh2005

macrumors 6502a
Jan 25, 2010
907
0
If it overheated, it would have shut down. Read my post, just before yours.
Your post, unless I'm misunderstanding it, is about the CPU overheating. What about other components? Is it not possible for a GPU to be overworked, causing a game to lock-up?
 

GGJstudios

macrumors Westmere
May 16, 2008
44,419
767
Your post, unless I'm misunderstanding it, is about the CPU overheating. What about other components? Is it not possible for a GPU to be overworked, causing a game to lock-up?
The CPU and GPU are the primary furnaces. No other components come close to generating the heat created by those two. Can your computer get extremely hot to the touch during periods of high demand on the CPU/GPU? Yes. Could a game lock-up due to a problem with the GPU? Probably. Could a game or other app lock up so bad that you have to reboot? Of course. That doesn't mean it overheated. It got very hot, but until it throttles or shuts down, it's still within the normal operating range, albeit at the high end of that range. Install iStat Pro to track accurate temps of your CPU and GPU and other components, instead of relying on how hot it feels or what happens to an app.
 

dh2005

macrumors 6502a
Jan 25, 2010
907
0
The CPU and GPU are the primary furnaces. No other components come close to generating the heat created by those two. Can your computer get extremely hot to the touch during periods of high demand on the CPU/GPU? Yes. Could a game lock-up due to a problem with the GPU? Probably. Could a game or other app lock up so bad that you have to reboot? Of course. That doesn't mean it overheated. It got very hot, but until it throttles or shuts down, it's still within the normal operating range, albeit at the high end of that range. Install iStat Pro to track accurate temps of your CPU and GPU and other components, instead of relying on how hot it feels or what happens to an app.
Thanks for the tip, but I don't have that computer anymore.


To address what seems to be the OP's central concern: iMacs certainly don't 'have an overheating problem'. The only episode, in a whole year of owning that computer that I 'perceived' to be due to overheating, was the one that I described. It is a massively, massively over-reported concern.
 

Macman45

macrumors G5
Jul 29, 2011
13,199
133
Somewhere Back In The Long Ago
I've never even had the fans rev on me. Intensive video work makes it slightly warm. Playing Bioshock (occasionally) doesn't cause the fans to kick in high either.

OP: Crysis is a very graphically intensive game. I've never played it on a Mac, so assume you are using Windows via bootcamp? I did play the whole series on a self built high end PC with 2 Nvidia 280 cards. That did cause the fans to kick in, but I never suffered a lock up. As GGJ posted, your mac is protected...It will shut itself down if critical temperatures are reached.
 

iSayuSay

macrumors 68040
Feb 6, 2011
3,256
387
It's hot. Generally hotter than the usual PC tower. But not necesarilly causing cpu damaged/crashed/inoperable.
But in my case it does burning out the lcd display and causing gray stains which spreading over time.
It is not affecting how the computer works, it's still working damn fine. But it's affecting how I work with the computer. :mad:


PS: I do use this iMac for gaming A LOT, maybe some video editing and occasional Photoshop. For people who feels fine with his/her own iMac, you might wanna try this. Games a lot with it maybe 10 - 15 hours a week continuously for 3 4 months period and see if your display still fine and no smudge after that :D
 
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iMarvin

macrumors 6502
Sep 29, 2011
268
2
On the internet!
It's hot. Generally hotter than the usual PC tower. But not necesarilly causing cpu damaged/crashed/inoperable.
But in my case it does burning out the lcd display and causing gray stains which spreading over time.
It is not affecting how the computer works, it's still working damn fine. But it's affecting how I work with the computer. :mad:


PS: I do use this iMac for gaming A LOT, maybe some video editing and occasional Photoshop. For people who feels fine with his/her own iMac, you might wanna try this. Games a lot with it maybe 10 - 15 hours a week continuously for 3 4 months period and see if your display still fine and no smudge after that :D
I game a lot of BF3, don't have no smudges. But i make sure my computer is cool, doesn't go over 70 degrees celsius at maximum load and rarely over 30 degrees celsius when just browsing.
 

forty2j

macrumors 68030
Jul 11, 2008
2,585
2
NJ
Applications like smcFanControl will give you the exact internal temperature and give you more fine tuning of the fan speed.

If you suspect that the fans are straining, always check the vents for dust, and clean out with a can of air as needed.
 

dawk84

macrumors newbie
Jun 25, 2012
2
0
The Real Issue

"Of course. That doesn't mean it overheated. It got very hot,"
Really? The problem is that it did not overheat, but it got too hot? From my perspective I see the computer has overheat protection, but I don't see how it is so hard to fathom that it is inadequate or has potential to fail. If your computer is overheating, the protection is not working. That is easy to see. Whether it is a manufacturer deficiency or a hardware malfunction, it is still nevertheless a failure of protective measures.
 
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GGJstudios

macrumors Westmere
May 16, 2008
44,419
767
Really? The problem is that it did not overheat, but it got too hot?
I didn't say that. I said it got "very hot", not "too hot."
If your computer is overheating, the protection is not working.
But the protection IS working. If it truly overheats, it will shut down to prevent damage. That IS the protection, and it works quite well. If it doesn't shut down, it's not overheating.
 

chevalier433

macrumors 6502a
Mar 30, 2011
510
13
The iMac's hard disk definitely have problem with heat mine failed in one and half year usage and was not my primary disk others failed much earlier who use it as their primary disk.
 
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dawk84

macrumors newbie
Jun 25, 2012
2
0
I didn't say that. I said it got "very hot", not "too hot."

But the protection IS working. If it truly overheats, it will shut down to prevent damage. That IS the protection, and it works quite well. If it doesn't shut down, it's not overheating.
Yes, the feature is supposed to shut it down if it overheats. What if the components fail to accurately read the temperature, or the system fails to shut down fast enough? You do not have to point out what the protection IS. If the computer breaks from heat, the protection is inadequate.
 
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wiznet

macrumors regular
May 30, 2012
165
1
Canada
Yes, the feature is supposed to shut it down if it overheats. What if the components fail to accurately read the temperature, or the system fails to shut down fast enough? You do not have to point out what the protection IS. If the computer breaks from heat, the protection is inadequate.
The funny thing is, is that your argument is almost completely irrelevant, and you have nothing to back yourself up with. As GGJ said, the protection is there, and it will not fail. If, for some reason, in another universe, an iMac didn't read the temperatures, and allowed for the machine to melt before your eyes, the logical solution would be to go to the Apple Store and get a replacement. But once again, that won't happen. The protection is there.

Who ever said anything about it breaking? It won't! That's the whole point of this.. there's protection there!
 

GGJstudios

macrumors Westmere
May 16, 2008
44,419
767
Yes, the feature is supposed to shut it down if it overheats. What if the components fail to accurately read the temperature, or the system fails to shut down fast enough? You do not have to point out what the protection IS.
Apparently, I do need to point out what the protection is, as you don't seem to understand. The CPU monitors itself and will shut down if Tjmax is achieved. It doesn't rely on other computer components to read the temps. If the CPU fails, you've got bigger problems than just worrying about heat.
If the computer breaks from heat, the protection is inadequate.
If it "breaks from heat" it's obviously defective, as that doesn't happen at all with non-defective models.
 

SandboxGeneral

Moderator emeritus
Sep 8, 2010
26,063
9,245
Detroit
I'll toss my experience in here as well. I've never had any heat issues with my 2 iMac's. This screen shot is of my 2.93GHz i7 ripping a DVD with Handbrake. As you can see, the cores are fully maxed out and I ripped about 10 DVD's that particular day and never had any issues at all. Yes the iMac heated up, which is expected, but it wasn't a problem.

 

ngenerator

macrumors 68000
May 12, 2009
1,835
0
USG Ishimura
I'll toss my experience in here as well. I've never had any heat issues with my 2 iMac's. This screen shot is of my 2.93GHz i7 ripping a DVD with Handbrake. As you can see, the cores are fully maxed out and I ripped about 10 DVD's that particular day and never had any issues at all. Yes the iMac heated up, which is expected, but it wasn't a problem.

Image
Totally off topic, but how long did it take to rip a DVD w/ Handbrake on your i7? Looking forward to getting my first quadcore ;)
 

russofris

macrumors regular
Mar 20, 2012
160
58
Hi,

I just curious if Imacs overheat. How do you know when they are too hot.
If operated within specification, an iMac will not overheat. If it does, there's a problem and you should escalate to Applecare. That said...

Any piece of technology can overheat if:
If operated outside of it's specified ambient temperature.
If ventilation is obstructed (by dust, an enclosure/cabinet, etc)
If thermal safeguards are overridden (you work in a music studio and have manually lowered the internal fan speed to reduce noise).

Newer tech tends to handle overheating in a graceful manner, lowering clocks and voltages in an effort to mitigate the effects and reduce permanent damage.

F
 

Morrius

macrumors member
Oct 23, 2007
95
0
Well, I didn't have the cause identified definitively but, when playing Crysis on a 2010 27" iMac, the final boss fight caused my computer to lock-up. The internal fans were blowing a gale - noisiest I ever heard the machine operating - then the graphics froze, the sound died, and I had to switch it off with the power button. The top of the machine was uncomfortably hot, when I checked.

In my semi-educated opinion, it overheated.
This has happened to me a couple of times before with WoW. It's not overheat, as far as I can tell. I think it's the graphics drivers exploding. But whatever it is, it's not a case of the CPU/GPU overheating. My MBP gets plenty hot, especially around the bezel where the fans are, but I haven't noticed any performance-related issues due to heat.
 

marzer

macrumors 65816
Nov 14, 2009
1,330
45
Colorado
Totally off topic, but how long did it take to rip a DVD w/ Handbrake on your i7? Looking forward to getting my first quadcore ;)
A typical movie DVD rip on my 2009 i7 is usually less than 15 minutes. Which is amazing considering it would take 15-20 minutes to rip a typical music CD on my Pentium computer back in 2000.
 

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