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Cooling Down a hot iMac

N

Nynas

macrumors newbie
Original poster
Dec 5, 2011
12
0
So...I have an odd question for an unique idea I have...

I have a late 2009 27" iMac, and as everyone knows they tend to run hot...mine runs so hot in fact that, even though I use a fan control program to keep my fan speed high, the GPU failed to days ago...probably due to heat.

I cannot afford a new computer so I am already going to have to do a DIY replacement of the GPU. But I still need to do everything I can to keep the computer cool...

So my idea is to build a mini AC strip that I can install under the computer to help feed cold air through the system. There are a number of ways to do this, the simplest just use ice. My question is, would the extra humidity from the ice/water evaporating damage the computer at all? I'd probably be using this thing all the time.

My other idea is to essentially strap some kind of liquid cooling system to the back of the case :p
 
The entire metal case acts like a radiator. You could just get a small fan and aim it at the back of the computer and that should help. Much simpler and cleaner than using water.
 
Nynas said:
So...I have an odd question for an unique idea I have...

I have a late 2009 27" iMac, and as everyone knows they tend to run hot...mine runs so hot in fact that, even though I use a fan control program to keep my fan speed high, the GPU failed to days ago...probably due to heat.

I cannot afford a new computer so I am already going to have to do a DIY replacement of the GPU. But I still need to do everything I can to keep the computer cool...

So my idea is to build a mini AC strip that I can install under the computer to help feed cold air through the system. There are a number of ways to do this, the simplest just use ice. My question is, would the extra humidity from the ice/water evaporating damage the computer at all? I'd probably be using this thing all the time.

My other idea is to essentially strap some kind of liquid cooling system to the back of the case :p
Click to expand...

Don't, it will for sure damage the iMac, cooled air needs to be dry, if it is not it will create condensation in the iMac.
If I were you I would buy just a small fan like the one below and point it to the back of the iMac.
But, yours is already 4 years old, if you get a new GPU in it and it goes another 4 years it's time to change the mac so I wouldn't do too much about it now, but that is up to you off course.


AZ-804PF_tn.gif
 
That is a good idea, and I'll probably start with that...But I am seriously aiming to keep this computer as cool as I possibly can.

before the gpu failed, if the computer got too hot the monitor would straight up shut off. The computer would have to be shut down and allowed to cool for awhile before getting it to work again, but an external display would still work. Now it doesn't even function anymore, only in safe mode where all graphical accelerators are turned off, even then there are these big blue bars across the screen.

I can't even do an Apple hardware test, because halfway through the computer gets too hot and the screen shuts off. Id never be able to see the results.
 
justperry said:
Don't, it will for sure damage the iMac, cooled air needs to be dry, if it is not it will create condensation in the iMac.
If I were you I would buy just a small fan like the one below and point it to the back of the iMac.
But, yours is already 4 years old, if you get a new GPU in it and it goes another 4 years it's time to change the mac so I wouldn't do too much about it now, but that is up to you off course.


AZ-804PF_tn.gif
Click to expand...

You know...I hadn't really thought about how old it is getting... I mean, it would only be about $250 to fix it, but should I just go ahead and get a new PC?
 
If it overheats doing the Apple Hardware test maybe you have other problems -- bad fan or inside clogged up with dust or pet fur? Or do you live in a tropical climate and have no air conditioning? My 2009 i7 will run for hours at a time at 100% CPU usage and never overheats (although it does get too hot to touch!).

----------
Nynas said:
You know...I hadn't really thought about how old it is getting... I mean, it would only be about $250 to fix it, but should I just go ahead and get a new PC?
Click to expand...
If it otherwise does what you need it to do, that's $250 versus about $2000. Seems like the repair is a better deal.
 
What actual temperatures are you seeing? My i7 27" late 2009 iMac can see 100% CPU usage for hours, as mentioned above, without overheating. The only time it has any indication of reaching upper temperature limits is when it's in direct sunlight in the summer (over 85°F ambient Temp). The aluminum case does get very hot to the touch, but the internal temps never go above intel's safe limits.

Don't introduce water vapor into your iMac please.

Since you're getting a new GPU, you might think about changing your HDD to a SSD to further reduce operating temps.
 
I ran my 2009 i7 27" iMac for 3.5 years at stock fan settings. Personally, I wouldn't worry about it. Your GPU died because it died, not because of heat issues I'd wager, especially since you had the fan speed turned up anyway. Get a new GPU and stop worrying about the system unless you live in a ridiculously hot environment.
 
I'm gonna wager when you open up your computer, you'll find the fans totally caked up with dust. I was having nothing but trouble with my 3-year-old C2D Macbook Pro until I opened it up and blew out the fans. They were disgusting. After that, my computer ran nice and cool for another 2 years before I replaced it.

Your fan control program may have contributed to this problem. By keeping the fans on high all the time, you're sucking up more dust into the system. I'd leave the fan settings on stock and just keep the computer clean. There's no reason it should ever overheat under normal operating conditions.
 
talmy said:
If it overheats doing the Apple Hardware test maybe you have other problems -- bad fan or inside clogged up with dust or pet fur? Or do you live in a tropical climate and have no air conditioning? My 2009 i7 will run for hours at a time at 100% CPU usage and never overheats (although it does get too hot to touch!).

----------


If it otherwise does what you need it to do, that's $250 versus about $2000. Seems like the repair is a better deal.
Click to expand...

100% cpu, but what about gpu? I opened up and air blasted out all the dust from my iMac (there was a lot) but running the hardware test in extended still shuts the screen off about 10-15min into it.

My guess is that at any time the gpu starts getting taxed or heats up there is an issue that causes the screen to shut off. I can run my computer in safe mode all i want, however nothing that uses any kind of graphical acceleration works, and there are those bars on my screen. I tried opening up a computer game just to see what would happen and it said "no graphics processor found."
 
I'll echo the idea of replacing the HDD with an SSD. If you're going to go through the effort of replacing the GPU, may as well do that too. It'll feel like a new machine and you'll get another couple years out of it.

I did this with my 2010 iMac and the performance is great. I bought an external enclosure and put the (formerly) internal 1TB drive in it and now use it for Time Machine backups. One observation: that drive runs really warm, even when it's not reading or writing. While it's not the culprit of heat problems in the iMac, I do notice my imac runs cooler with the SSD installed (I've got SMC Fan Control installed).
 
Nynas said:
100% cpu, but what about gpu? I opened up and air blasted out all the dust from my iMac (there was a lot) but running the hardware test in extended still shuts the screen off about 10-15min into it.

My guess is that at any time the gpu starts getting taxed or heats up there is an issue that causes the screen to shut off. I can run my computer in safe mode all i want, however nothing that uses any kind of graphical acceleration works, and there are those bars on my screen. I tried opening up a computer game just to see what would happen and it said "no graphics processor found."
Click to expand...

I feel your pain. My first personal mac, my 2006 Macbook Pro had a graphics card failure, it would run 'fine' too in safe mode, well it had checkerboarding all over the screen, but it shows that it was the GPU at fault, but at that old it just wasn't viable to have it replaced, but now I have a beautiful new imac. I know you said you cant afford to replace, but if yuo could replace the logic board with a new one, maybe you should take a look and try and reflow your old one, get a bit more use out of it :)
 
Nynas said:
100% cpu, but what about gpu? I opened up and air blasted out all the dust from my iMac (there was a lot) but running the hardware test in extended still shuts the screen off about 10-15min into it.
Click to expand...

Might cause problems as well, but I don't think I ever tax my GPU that much (Aperture uses the GPU but not on a continuous basis, and everything else I do that's intensive is CPU intensive.)
 
i got my local apple certified repair guys to go inside the imac and blow every bit of dust out of it and i am definitley running 10 degrees cooler i got a 2010 one
 
We have a 21 and 27" late 09 iMacs, both run hot, the 27" is the worst it turns my office into a hot box, I couldn't take it anymore and a month a go got a 15" MBPr and now it hardly gets used. Makes a good TV though. I wouldn't get another imac unless it has retina and then probably a 21".

ps SMC fan control helps a bit.
 
Nynas said:
So...I have an odd question for an unique idea I have...

I have a late 2009 27" iMac, and as everyone knows they tend to run hot...mine runs so hot in fact that, even though I use a fan control program to keep my fan speed high, the GPU failed to days ago...probably due to heat.

I cannot afford a new computer so I am already going to have to do a DIY replacement of the GPU. But I still need to do everything I can to keep the computer cool...

So my idea is to build a mini AC strip that I can install under the computer to help feed cold air through the system. There are a number of ways to do this, the simplest just use ice. My question is, would the extra humidity from the ice/water evaporating damage the computer at all? I'd probably be using this thing all the time.

My other idea is to essentially strap some kind of liquid cooling system to the back of the case :p
Click to expand...

Nynas, ever get this back up and running cool?
 
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