acceptable temperature for G5 iMac

Re: CPU and HD temperature. The prevailing opinion on this board is to simply not worry about temperature, since the unit will shut down if it gets dangerously hot. This ignores the apparent numbers of these that have temperatures in the upper limits, just beneath the point where the unit will shut off.

Since heat is the enemy of electronics and the G5 Imacs run far hotter than other Macs (my G4 MDD DP 1.25 runs _ 20 DEGREES F COOLER+_ than my 20" ALS 2Ghz Imac) it stands to reason that the failure rate is driven by heat related issues.

I've taken every precaution to make sure my Imac is as cool as possible; i.e. installation of CHUD 3.5.2 with 'nap' feature enabled (covered in a previous post), a foil heatsink attached to the HD (this lowered HD temps 15+ degrees F) and of course frequent vacuuming of the cooling passages and vents.

All of the above keeps the CPU temps under 120 F for most apps, rising occasionally to around 130 F with CPU intensive apps (large graphics in Photoshop CS2). The HD ranges from 106 F to 113 F. I'm appalled when reading that users here have CPU temps between 140 - 170 F.

The more users ignore the temperature issues, the sooner they'll have their units in for repair of (pick one) logic board, hard drive or power supply.

Your temps seem in line with my Rev A, I wouldn't worry about them, they're normal.

Miriam

The temps you posted were normal, but sleeping during an operation is indicative of a temperature problem. Look in Console for a system log entry that says something like " maximum temperature exceeded for more than 30 seconds".

Miriam

It could be that your temp sensors are faulty, which is why they report excess heat, or it could be that you are indeed having a problem with your power supply unit, which would again, cause the excessive temps. Take a look and see if you're included in this Apple program: power supply or video and power issues.

Please post back and let us know,

If you are having some high temperatures take a look between the stand and the computer, near the pivot. There is a circular vent there that is easy to miss when you are cleaning and may be clogged with lint.

<<been having the same shutting down issue. I just got a new logic board <<installed, brought it home and it did the same old shut down. Checking the <<temperatures and console I see that i too had the 'temp exceeded for 30 <<seconds' error, etc.

<<Are you suggesting that the only fix is the 'installation of CHUD 3.5.2 with <<'nap' feature enabled (covered in a previous post), a foil heatsink attached <<to the HD (this lowered HD temps 15+ degrees F) and of course frequent <<vacuuming of the cooling passages and vents.' ???>>

No. You have a hardware problem that hasn't been corrected yet. Return your computer to the repair facility and have the problem corrected.

You have an Isight G5, so you can't add an internal HD heat sink; they're not internally user serviceable. I have an ALS Model, which I added the HD heatsink to and reduced HD temperatures significantly.

Using CHUD (an Apple utility) is ALWAYS a good idea, since the all-in-one design of the Imac coupled with the heat produced by the G5 970 chip means that these things generate a lot of heat and temperatures run much higher than a comparable G5 tower.

CHUD 3.5.2 is simply software (from Apple) that allows the processor to 'nap' between cycles when not at high usage and reduces processor temps pretty dramatically. I've not noticed any performance decrease, having used it on G4s as well as all my current G5s.

Once your machine is repaired correctly, it will run without reaching shut-down temperatures.

Be wary of advice on this board that the Imac PPC G5 temperatures are 'normal' and not a critical issue. Heat is always the enemy of electronics; doing what you can to keep it in check is prudent and will prolong your machine's operating life.

Good luck.

Hello:

The only Apple temperature documentation I found is the operating temperature, not the internal temperatures you note. I am not trying to be funny, but why spend time (and computer resources) monitoring what the computer does itself (and shuts down if the temperatures are out of range)?

Barry

You got a faulty motherboard replacement - call your repair place and have it fixed properly. Once you have properly functioning replacements, you will have a computer that works properly. There's no need to mess about with CHUD.

There's an interesting photo taken by Popular Mechanics with a heat sensitive camera. Note the temperatures around the Hard Drive and processor. Go to google and type in 'iMac G5's running too hot'

Message was edited by: cwmmjm

Message was edited by: cwmmjm

YES! That is exactly what I found in my system log... "maximum temperature exceeded." That explains why it keeps shutting off on me. Ahhh! It's lovely to at least have a reason WHY.

I installed Temperature Monitor so I can keep an eye on the temp and ease off on what I'm doing once I start nearing the max temp (which it tells me is 85 C/ 185 F)... mine is consistently in the high 70s (in the 170s Fahrenheit). Um, that can't be normal, can it?

So, clearly it shouldn't be always on the brink of a shutdown due to high temps... what's the cause of this? (I had a new fan installed a few months ago after I noticed it was constantly making lots of noise... maybe the new fan is faulty??)

Hi, I've been having the same shutting down issue. I just got a new logic board installed, brought it home and it did the same old shut down. Checking the temperatures and console I see that i too had the 'temp exceeded for 30 seconds' error, etc.

Are you suggesting that the only fix is the 'installation of CHUD 3.5.2 with 'nap' feature enabled (covered in a previous post), a foil heatsink attached to the HD (this lowered HD temps 15+ degrees F) and of course frequent vacuuming of the cooling passages and vents.' ???

Even if I get a new power supply, my computer will continue to crash out?

Thanks,
Jonathan

yes, thanks miriam. I am planning to take it back tomorrow. I installed the X Resource Graph and I have some numbers in the 160-170's but not sure which are the relevant numbers:

CPU T-Diode = 171 degrees
GPU Temp = 168.8
Nb Temp = 173

Which one is the relevant one? Thanks!!!

<<an interesting photo taken by Popular Mechanics with a heat sensitive camera. Note the temperatures around the Hard Drive and processor.>>

....................................................................

Thanks for posting this.

Re: Is The iMac G5 Running Hot?
POPULAR MECHANICS looks into the reliability of Apple's groundbreaking desktop.

For the naysayers and other interested parties, read the article here:

http://www.popularmechanics.com/technology/upgrade/1707756.html

Also interesting in the body of the article is the reported 31% failure rate for the Rev. A 20in G5 Imac.

As I've said in numerous posts here, do what you can to keep the temperatures down.

Thanks for the info Bosco45! You mentioned that you've got foil heat sinks on you iMac. By chance do you know if these will fit the slightly elder first generation iMac 1.8ghz 20"? If so, where can I get em? I'm really really worried that these things are going to fry the next time I use them. And I really don't see how the hard drive is cooled at all in these. There is a large blower that goes thru the heat sink then a case fan on the board side. The only thing that I can see there is to cool the hard drive side is an itty bitty little fan down on the bottom of the case next to where it draws air in for the processor. This makes no sense...No hard drive fan? Could that be a reason these things cook?

Thanks,
Robert